Why do I need a default gateway in tcp/ip windows properties?

Question

Computer networks

Please give an intelligible explanation and advise which literature to read.

Answer 1

To answer this question, you need to understand how addressing works in TCP/IP networks.
When your PC is, for example, on a home network, then the scope is limited to this very network that was set by the network mask and address.
But you need to somehow access the Internet in order to write a question on toster.ru, which, in turn, is located on another network that is not available to you. To get into it, you need to forward your packets through some intermediate device / interface that knows how to deliver your packets exactly where you want.
A life analogy is when you are standing on the first floor of a house, and you need to get to the sixth. To do this, you use the elevator, which you order to stop exactly on the sixth floor (he knows where the sixth is). In this case, the elevator is the gateway.
Regarding your question - this gateway may not exist. Then you can only work in the current network.
This is the simplest example.

Answer 2

The best book on
Olifer and Olifer networks (also known as "olifers" or "olifer's textbook")