Lua implements a single data structure type, which is implemented as a general-purpose collection that encompasses functionality that is usually implemented by several different data structures in other programming languages. This makes tables powerful, but can also make it a bit challenging to work with, and can lead to surprising results if one is not careful. For example, while tables can act as both lists and mappings, most table functions generally make an assumption about how the table is being used. When a table function is used in the wrong context it won't generate an error, it will just return an unexpected result.
We will learn much more about tables in the Tables chapter.