genuine html question

Hey so serious question here!!

I want to make a guest book for my site, so I made a button link and got the comment box done. But im not sure what the form method means, I know I need that so the comments can be actually posted. But the language used when reading some tutorials is a bit confusing to me as I am very rusty with HTML.

Im not sure if I'll implement it as a permanent feature as managing comments by hand seems tiresome. But I just want to know how to do it for the sake of learning, as my HTML skills are basic and rusty. i took courses 8 years ago, I took way more classes in learning C# and C++ so HTML is fun and new for me in a sense