DTints, What are they and how are they used?

Hello facepunch,
I’m trying to learn about what DTints are and how they work, so i can create variables usable on a weapon. I’ve read the entry for the Gmod Wiki, But it made no sense to me. Same for the entry on luasearch.
Could someone here please explain in depth what a DTint is?
Here’s an example for those who dont know what im talking about:

Entity:GetDTInt(  Int, Key )

TIA, Archemyde

It returns the a data table interger. DTVars are like netoworked vars but will be less expensivenand are limited.

Thanks, I delved in further and asked around and got what i was looking for.