This Episode introduces data structures, focusing on lists and linked lists within the context of A Level Computer Science. It begins by defining abstraction and abstract data types (ADTs), using a queue and a list as examples, highlighting that ADTs allow users to interact with data and operations without knowing their underlying implementation. The material then differentiates between static and dynamic data structures, explaining that static structures have fixed sizes while dynamic ones can change, with many programming languages offering built-in dynamic list support. The document further outlines common operations for lists such as adding, removing, sorting, and searching, and provides pseudocode examples for implementing a queue using a dynamic list. Finally, it elaborates on linked lists as a dynamic ADT implemented with arrays and pointers, detailing how nodes, data, and pointers work together, and illustrating how to add and delete elements within this structure.