Definition: An Abstract Data Type (ADT) is any reasonably complex type that isn't one of the standard types- int, float, string or array.
The C++ STL (Standard template Library) implements several ADTs such as lists and vectors.
Glossary:
A B C D E F G H I J K L M N O P Q R S T U V W X Y ZExamples:
I rewrote the algorithm to use an ADT and decreased the application's processing time.

