A firewall basically consists of a software utility, or hardware device, that acts in the same way as a filter would, admitting or preventing the entry or exit of data from a network or computer.
We could identify him as a kind of security guard, whose job is basically to decide who enters or who leaves our building. In this way, a firewall works by blocking or restricting network ports .
As we will see next, a firewall is tremendously useful in helping to prevent and avoid unauthorized access not only to the networks belonging to a company, but also to our own home network.
In this way, a firewall is located between a computer or local network, and another network, as for example could be the case of the Internet, controlling both incoming and outgoing network traffic .
Returning to the previous example, if our building did not have a security guard who controlled access to it, obviously anyone could access it, including people who do not have a home in it. Therefore, as far as our computer or local network is concerned, without a firewall or firewall, everything would be valid .
However, with the help of the rules established by the firewall, we will determine which traffic is allowed and which is not .
What is a firewall or firewall for?
For home users, one of the main security purposes of a firewall is to block unsolicited incoming network traffic . But the truth is that they can carry out more interesting functions.
For example, since there is a firewall between the network and the computer, it is possible to analyze all the incoming and outgoing traffic on the network , and decide, accordingly, what we can do with it.
Thus, the firewall can be configured to block certain types of outgoing traffic, or to record suspicious traffic (or, in short, practically all traffic). It is even possible to have a wide variety of rules that deny or allow certain types of traffic, being able to only allow connections to a specific server from a certain IP address, discarding the rest of the connection requests.
But its uses and advantages go much further, and we can discover them little by little in our day to day life.
