Questions about the Bitcoin Software. ( DNS Seed & Chainparams )

[uycoin]

Hello, I would like to know. What is a Seed Nodes / DNS Seed ?

Used as alternate boot method ? someone can better explain.

Seed Nodes:
    - Nodes whose IP addresses are included in the Bitcoin client for use during a new installation when the normal bootstrapping process through IRC wasn't possible.

I try to understand this project: https://github.com/TheBlueMatt/dnsseed

I see used here: https://github.com/bitcoin/bitcoin/blob/master/src/chainparams.cpp#L144

I try to understand this file (chainparams.cpp), I want to try to create a coin in a test environment, to understand the bitcoin system.

I appreciate any help.

Thanks!