Computer Science is the study of computation, algorithms, data structures, and the principles behind how software and hardware work.

Algorithms

An algorithm is a step-by-step procedure to solve a problem. Key properties: it must be finite, unambiguous, and produce a correct output for valid input.

Data Structures

• Array — a fixed-size ordered collection of elements of the same type
• Linked List — elements (nodes) are linked together using pointers
• Stack — Last In First Out (LIFO) structure; like a stack of plates
• Queue — First In First Out (FIFO) structure; like a line of people

Binary Number System

Computers store all data in binary (base 2) using only 0s and 1s. Each digit is called a bit. 8 bits = 1 byte.

Example: 1010 in binary = 10 in decimal (1×8 + 0×4 + 1×2 + 0×1)

Programming Logic Basics

• Sequence — instructions run in order, one after another
• Selection — if/else conditions choose different paths
• Iteration — loops repeat a block of code multiple times