starting from line 132, I see the function
vSeeds.emplace_back("seed.bitcoin.") and next to them there are real full names. What do seeds do? What are these lines for? What is the meaning of those names? Can someone give a technical detail please?
In order for a bitcoin node to start connections with other nodes, it first needs a seed node. A seed node can be any node (listening) connected to the bitcoin network. Once the node has connected to the initial seed node, it can then retrieve information about other nodes in the network and start connections with those ones as well.
The names you are seeing in the source code are the URLs of some of the bitcoin core developers that host seed nodes. If you don't trust these crazy cypherpunks, you can actually specify your own seed node in your
bitcoin.conf under the option
Those hosts are DNSseeds.
When your node starts if it find itself unable to successfully connect to the network within 11 seconds it will query those DNS names which are run by technical people in the Bitcoin community, and get back a lists of recently working nodes.
The use of DNS improves your privacy somewhat since DNS caching can prevent the operator's name server from seeing the request at all and if it isn't cached they usually won't see your IP address, instead they'll see the IP of your ISPs recursive resolver. (Of course, the fact that it skips the use of it entirely if it can get connected also improves your privacy).
You can disable use of these dnsseeds by setting -dnsseed=0.