Answer 1

Class templates are a kind of template.
The symbols to fill them in are data types.
Class templates are supported by many programming languages including Java, c++, c#. In Java, an example is its java.util.LinkedList. You could make a list specifically of integers described in Java by java.util.LinkedList<Integer>. In those languages, class templates have the benefit of more precisely defining data type for variables and parameters. They also allow the compiler to do more optimization without programmers having to write more code.