How does wget redownload a file?

Question

Web servers

Good day!
I thought about the question "How does wget re-download a file?", if the connection to the server was lost, then the connection appeared, then according to the logic of http (s) we re-establish the connection and get the requested file from the beginning. Wget remembers how many bytes it has downloaded, and starts skipping newly received bytes until new ones are received, those that have not yet been received.
Do I understand correctly that "re-downloading" is just the name of a re-download (trying to download until we download) or not?
Is it possible to configure the server (Nginx, Apache) so that it would request a file from the moment of the break? Or is it necessary to write your own server?

Answer 1

For re-downloading, you need the server to support the http header Range
About support for Range by the nginx server is written here

Answer 2

> and get the requested file first
here you have two errors. the HTTP protocol allows you to download from anywhere, not just from the beginning.