A list can be defined as a data structure in Python, a Software Engineering concept, which is a mutable and organized sequence of elements. Every value or element in the list is called an item. Lists are the values defined between square brackets [ ] just like the strings are defined through the characters between the quotes. It is a compound data type that can contain different data types under the same list; for example, A programmer can define integer, float, and string in the same list. 

A list in Python is created by placing values inside the square brackets [ ], and each value is separated using commas. A list can have n number of items and can be of different data types (float, double, integer, string, etc.). A nest can also be defined inside another list which is called a nest list. 

Python lists can store multiple items in a single variable. In Python, lists are one of the four data types used to store data collection along with tuples, sets, and dictionaries. These data types have different qualities and are used for different purposes. It allows the programmer to use different data types in a single list; for example, one can define float, integer, string, and double in the list. 

The key difference between list and tuple in Python is that lists are mutable, which means the values can be modified even after they are defined while tuples are immutable, which means tuples are not modifiable once they are defined. Tuples are also more memory efficient than lists. 

Yes, you will get a certificate of completion for Python List after completing all the modules and cracking the assessment. The assessment tests your knowledge of the subject and badges your skills.