A tuple type is an ordered sequence of possibly different types enclosed in parenthesis:

type MyTuple = (Nat, Text);

Here is a variable with the MyTuple type.

let myTuple: MyTuple = (2, "motoko");

We can access the values of the tuple like this:

let motoko = myTuple.1;

By adding .1 to myTuple we access the second element of the tuple. This is called tuple projection. The indexing starts at 0.

Another example:

let profile : (Text, Nat, Bool) = ("Anon", 100, true);

A tuple type is created and used without using an alias. The variable name profile is annotated with the tuple type. The value assigned to the variable is a tuple of values ("Anon", 100, true);

We access the first element like this:

let username: Text = profile.0;