It is a special method used for user friendly string representation of an object.

There are two types of errors; 1. Syntax Error (i.e code not following the rules of the language) 2. Logic Error (i.e the program executes but generates wrong results) <- These types of runtime errors are also called exceptions.

The study of data structure helps us to understand the implementation of those data structures like arrays, queues, stacks, etc.

The study of abstract data types helps us to focus on the implementation of the solution rather than focusing on the details of their implementation. e.g. of abstract data type, lists, dictionary, tuples, etc.