Why do JAVA projects have such a different folder structure?

Question

Java

Good afternoon!
I am not a JAVA expert, but I am digging in this direction.
Why do different projects have such a different folder structure? I saw many examples of this chaos.
-- Somewhere there is a build folder, but somewhere not.
-- Somewhere there is WebContent, but somewhere there is not.
-- For one project, the META-INF folder is located like this, and for the other, that way.
-- Somewhere in src packages are immediately stored, and somewhere there is all sorts of crap stuffed in there.
At the same time, there is an assumption that the structure of the project is not born from the imagination of the creators, but comes from the requirements of the applied technologies. Is the guess correct?
What to read in order to understand the meaning of just this, and not another layout of the project folders?

Answer 1

build - by default in eclipse is the directory for compiled classes, if the maven project is /target/classes.
META-INF again...may not exist at all, but be generated during assembly...
In general: the structure correlates with the project type. At the same time, the possibility of "own" placement is preserved
Read - for each project, its own assembly file. Here it is to look into it in order to understand why it is so.