What is the difference with making a table these ways?

Hello developers, I am making a character customization system and saving it with profile service, and I am use to making tables like this

local table = {}

but in the saving system I see other developers who stream and I see they save theirs like this

{
   hairs{
bla bla bla
}
}

etc. how does it work with {
{

}
}

like how do I reference it? how do I use it?

Well table is a value so it would be the same as any other value put into a dictionary with no key attached to it.

It would just be sorted an array number

local t = {
  {},
  false
  1,
}

print(t[1])