[Skip to content](https://www.t-mobile.com/home-internet/the-signal/internet-help/what-is-a-firewall#maincontent) [The Signal](https://www.t-mobile.com/home-internet/the-signal) - [Speed](https://www.t-mobile.com/home-internet/the-signal/category/speed) - [Internet Devices](https://www.t-mobile.com/home-internet/the-signal/category/internet-devices) - [Internet Help](https://www.t-mobile.com/home-internet/the-signal/category/internet-help) - [All Blogs](https://www.t-mobile.com/home-internet/the-signal/latest) - [ISP](https://www.t-mobile.com/home-internet/the-signal/category/isp) - [Speed](https://www.t-mobile.com/home-internet/the-signal/category/speed) - [Internet Devices](https://www.t-mobile.com/home-internet/the-signal/category/internet-devices) - [Internet Help](https://www.t-mobile.com/home-internet/the-signal/category/internet-help) - [All Blogs](https://www.t-mobile.com/home-internet/the-signal/latest) - [ISP](https://www.t-mobile.com/home-internet/the-signal/category/isp) 1. [The Signal](https://www.t-mobile.com/home-internet/the-signal) 2. Category:[Internet Help](https://www.t-mobile.com/home-internet/the-signal/category/internet-help) [Internet HelpCategory](https://www.t-mobile.com/home-internet/the-signal/category/internet-help) # What is a Firewall and What Does It Do? Published: May 13, 2025 |6 min read Whether you're surfing the web, streaming your favorite shows, playing games, or doing just about anything online, your home internet is constantly exposed to threats. Malicious software, viruses, and hackers are always lurking, ready to cause trouble-making [security](https://www.t-mobile.com/home-internet/the-signal/internet-help/5-next-level-security-wi-fi-tips-for-home) more important than ever. Ahí es donde algo llamado cortafuegos es muy útil. ¿Pero qué es exactamente un cortafuegos y cómo ayuda a proteger tus dispositivos y tu información personal? Let's dive into it so you can better understand how this essential tool works to [keep your online world safe](https://www.t-mobile.com/home-internet/the-signal/speed/wi-fi-security-essential-protections).  1 #### Jump to a Section 1. [The firewall: How it protects computers, network devices & more](https://www.t-mobile.com#firewallh2) 2. [Does the average person really need a firewall?](https://www.t-mobile.com#average) 3. [How does a firewall work?](https://www.t-mobile.com#firewallworks) 4. [Stateless vs. stateful firewalls](https://www.t-mobile.com#statelessvsstateful) 5. [Hardware vs. software firewalls](https://www.t-mobile.com#hardwarevssoftware) 6. [¿Cuál deberías elegir? Probably both.](https://www.t-mobile.com#whichone) - Share "What is a Firewall and What Does It Do?" on X - Share "What is a Firewall and What Does It Do?" on Facebook - Share "What is a Firewall and What Does It Do?" on LinkedIn ## __The firewall: How it protects computers, network devices & more__ A firewall is a security system that acts like a digital barrier between connected devices and the outside world (the internet). Imagínatelo como un guardia de seguridad que controla quién puede entrar y quién no. Un cortafuegos supervisa el tráfico (datos) que fluye entre tus dispositivos e Internet, y decide si permite o bloquea esos datos en función de un conjunto de reglas de seguridad predeterminadas. Esta herramienta sencilla pero poderosa puede impedir que los hackers accedan a tus datos personales, protegerte de sitios web maliciosos y evitar que apps no autorizadas envíen tus datos a Internet. Whether it's your computer, smartphone, or router-firewalls are crucial for maintaining a safe and secure network. ## __Does the average person really need a firewall?__ When you think of cyberattacks and data breaches, it may seem like they only happen to big companies-since those stories tend to make the news. The fact is, cyberattacks and breaches can happen to anybody, anytime-and firewalls give you crucial protection against: - __Hackers trying to break into your home network__ - __Malware and viruses that can infect your personal devices__ - __Phishing attacks and other online scams__ - __Unauthorized access to your personal data__ Simply put, a firewall is your first line of defense against the dangers lurking on the internet. By controlling and filtering the traffic that flows in and out of your devices-a firewall helps keep your personal information, data, and devices safe from hackers and malware. ## __How does a firewall work?__ Now that we know what a firewall is, let's break down exactly what it does. A good firewall will: - __Check incoming and outgoing traffic.__ A firewall checks the data packets that travel between your device and the internet. (Piensa en los paquetes de datos como pequeños sobres digitales que contienen información importante). It makes sure nothing harmful is coming in and that no sensitive information is being sent out. - __Block unauthorized access.__ If a hacker tries to access your network or a suspicious app tries to send data without your permission, the firewall will block it, keeping your network safe. - __Filter content.__ Many firewalls allow you to set up specific rules to block certain types of content or websites. If you want to prevent access to social media sites or block harmful content for kids, a firewall can do that. - __Monitor activity.__ Firewalls also keep track of the activity happening on your network. Pueden detectar comportamientos inusuales, como un intento de conectarse a una dirección de IP sospechosa, y alertarte de posibles amenazas. In a nutshell, firewalls are the first line of defense for protecting your home internet network. ## __What is a stateless vs. stateful firewall?__ When it comes to firewalls, not all are created equal. Hay dos tipos principales: cortafuegos sin estado y cortafuegos con estado. The difference between them can affect how well your network is protected and how much traffic can flow through. ### __Stateless firewall.__ A stateless firewall works by checking each individual packet of data on its own, without "thinking" about the context or state of the connection. En otras palabras, analiza cada dato y decide si lo permite basándose en reglas predefinidas, sin rastrear toda la conversación entre tu dispositivo e Internet. This has some pros and cons: - __Pros:__ Stateless firewalls are usually faster since they don't have to keep track of the entire connection. They work well for basic tasks like blocking unwanted traffic or simple filtering. - __Cons:__ Because they don't track the state of connections, they can miss more sophisticated attacks or unauthorized access that tries to exploit multiple packets over time. ### __Stateful firewall.__ A stateful firewall tracks the entire conversation between your device and the internet, making it much smarter. Puede realizar un seguimiento de las conexiones activas, lo que le permite analizar el flujo de tráfico y tomar decisiones más informadas sobre si debe permitir o bloquear los datos. Piensa en ello como si se tratara de una persona que está siguiendo el hilo de toda una conversación en lugar de limitarse a responder a cada comentario individual. Here are the pros and cons: - __Pros:__ Stateful firewalls give you better security because they can understand the entire context of data packets. They are more effective at detecting complex attacks and malicious behavior over many data packets and sessions. - __Cons:__ Because they're more thorough, they can slow down devices or networks that don't have the processing power to keep up. También suelen ser más caros y más complejos de gestionar. Por lo tanto, aunque ambos tipos de cortafuegos pueden proteger tu red, los cortafuegos con estado te ofrecen la protección más sólida y fiable. However, they may be a bit of overkill for the average household-and they may slow things down. ## __Hardware vs. software firewalls__ When it comes to firewalls, you'll typically see two types: hardware firewalls and software firewalls. Here's a closer look: - __Hardware firewalls__: These are actual physical devices that sit between your home network and the internet (in most homes, it's a [router or gateway](https://www.t-mobile.com/home-internet/the-signal/internet-devices/pros-and-cons-of-using-a-gateway-vs-router-and-modem).) Supervisan y controlan todo el tráfico que entra y sale de tu red doméstica, lo que te proporciona un nivel de protección centralizado y superior. These are especially good for large homes-or homes with a lot of connected devices. - __Software firewalls__: These are programs installed directly on your individual devices, like your computer or smartphone (e.g., Windows Defender, McAfee Total Protection, Norton 360, etc.) They monitor and filter traffic just for that device. They're great for personal protection on a per-device basis and are usually easy to set up. ## __Which one should you choose? Probably both.__ - If you have lots of devices like phones, laptops, gaming consoles, smart TVs, smart assistants, etc. and want a simple, centralized security solution, a hardware firewall is essential. Most modern routers and gateways come with a built-in firewall, so you likely already have one in place. - If you want even more protection for specific devices (such as your work computer), then adding a software firewall is probably a good idea, too. Al final, estos cortafuegos se complementan entre sí, proporcionándote capas adicionales de protección para tu red doméstica. T-Mobile is the fastest-growing [Home Internet](https://www.t-mobile.com/home-internet) provider, delivering [Advanced Cyber Security](https://www.t-mobile.com/support/home-internet/advanced-cyber-security) on its [All-In Plan](https://www.t-mobile.com/home-internet/plans/all-in-unlimited-internet-plan), as well as its [Amplified Home Internet Plan](https://www.t-mobile.com/home-internet/plans), for added peace of mind. Esto te proporciona capas adicionales de seguridad, como Navegación segura, que ayuda a bloquear enlaces maliciosos, y Detección de anomalías, que protege tus dispositivos conectados frente a los ciberdelincuentes. Best all, you can easily manage everything through the [T-Life app](https://www.t-mobile.com/apps). See [which plans are available](https://www.t-mobile.com/home-internet/eligibility) near you. ##### __Explore Wi-Fi Security__ [Security And Wi-Fi: How VPNs Work](https://www.t-mobile.com/home-internet/the-signal/internet-help/security-and-wifi-how-does-a-vpn-work) [101 Guide to Wi-Fi Subnet Masking Networks](https://www.t-mobile.com/home-internet/the-signal/internet-help/guide-to-wifi-subnet-masking-networks) [What NAT Type Is & How To Change It](https://www.t-mobile.com/home-internet/the-signal/internet-help/what-nat-type-is-and-how-to-change-it) Sources: [https://www.cisa.gov/news-events/news/understanding-firewalls-home-and-small-office-use](https://www.cisa.gov/news-events/news/understanding-firewalls-home-and-small-office-use) [https://www.pcmag.com/explainers/do-you-need-a-personal-firewall](https://www.pcmag.com/explainers/do-you-need-a-personal-firewall) [https://us.norton.com/blog/privacy/firewall](https://us.norton.com/blog/privacy/firewall) [https://www.fortinet.com/resources/cyberglossary/how-does-a-firewall-work](https://www.fortinet.com/resources/cyberglossary/how-does-a-firewall-work) [https://www.connectwise.com/blog/cybersecurity/stateful-vs-stateless-firewall](https://www.connectwise.com/blog/cybersecurity/stateful-vs-stateless-firewall) [https://www.fortinet.com/resources/cyberglossary/stateful-vs-stateless-firewall](https://www.fortinet.com/resources/cyberglossary/stateful-vs-stateless-firewall) [https://www.t-mobile.com/news/network/t-mobile-new-home-small-business-internet-plans-value-benefits](https://www.t-mobile.com/news/network/t-mobile-new-home-small-business-internet-plans-value-benefits) [https://www.cisco.com/site/us/en/learn/topics/security/what-is-a-firewall.html](https://www.cisco.com/site/us/en/learn/topics/security/what-is-a-firewall.html) Tags - [Security](https://www.t-mobile.com/home-internet/the-signal/archive/security) - [Technology](https://www.t-mobile.com/home-internet/the-signal/archive/technology) - [VPN](https://www.t-mobile.com/home-internet/the-signal/archive/vpn) ## Related Articles NEW [Read More](https://www.t-mobile.com/home-internet/the-signal/internet-connection/how-does-the-internet-work) [](https://www.t-mobile.com/home-internet/the-signal/internet-connection/how-does-the-internet-work) [Internet Connection](https://www.t-mobile.com/home-internet/the-signal/category/internet-connection) ## [How Does the Internet Work? A Simple Explanation](https://www.t-mobile.com/home-internet/the-signal/internet-connection/how-does-the-internet-work) June 3, 2026 NEW [Read More](https://www.t-mobile.com/home-internet/the-signal/internet-help/new-internet-or-transfer-internet-moving) [](https://www.t-mobile.com/home-internet/the-signal/internet-help/new-internet-or-transfer-internet-moving) [Internet Help](https://www.t-mobile.com/home-internet/the-signal/category/internet-help) ## [New Internet or Internet Transfer When Moving: What's Best?](https://www.t-mobile.com/home-internet/the-signal/internet-help/new-internet-or-transfer-internet-moving) April 22, 2026 NEW [Read More](https://www.t-mobile.com/home-internet/the-signal/speed/ethernet-vs-wifi) [](https://www.t-mobile.com/home-internet/the-signal/speed/ethernet-vs-wifi) [Speed](https://www.t-mobile.com/home-internet/the-signal/category/speed) ## [Ethernet vs. Wi-Fi: Which Connection is Best for You?](https://www.t-mobile.com/home-internet/the-signal/speed/ethernet-vs-wifi) April 29, 2026 ### Find out if your home address is eligible for T-Mobile 5G Home Internet. [Check availability](https://www.t-mobile.com/home-internet/eligibility) Top