Stanford CS105: Intro to Computers | 2021 | Lecture 1.1 Bits, Bytes, & Binary: It's all about 0 & 1

Introduction to Binary Numbers00:00:11

Computers operate using the binary number system, which differs from the decimal system we commonly use. The decimal system (base 10) uses ten digits (0-9), while the binary system (base 2) uses only two digits: zero and one. All numbers in a computer are represented using these two binary digits.

Why Computers Use Binary00:01:15

Computers use binary because their memory consists of electronic switches that can be either on or off, similar to a light switch. An 'off' switch represents a zero, and an 'on' switch represents a one. Each of these single digits (zero or one) is called a 'bit,' which is a shortened form of 'binary digit'.

Bits and Bytes00:02:06

A single bit offers limited utility, so bits are grouped together. The primary grouping is a 'byte,' which consists of eight bits. The byte is the fundamental unit for measuring computer storage.

Data Storage in Bits and Bytes00:02:21

All computer data, whether in main memory or other storage mediums, is ultimately stored as bits and bytes. Different storage devices represent these zeros and ones in various ways: SSDs use electronic switches, hard disks use magnetic polarity, and CDs/DVDs/Blu-rays use pits and lands. Regardless of the method, the underlying principle is the representation of information as zeros and ones.