APCSP CHEAT SHEET
Unit 1: Computing & Problem Solving Unit 2: Data & Binary
Computer science focuses on using computers Data is made up of raw facts, while information
to solve problems. A computer follows is data that has been processed to have
programs, which are sets of instructions written meaning. Computers store all data using the
by humans. Because computers only do what binary system, which consists of 0s and 1s. A
they are told, instructions must be clear and single binary digit is called a bit, and eight bits
precise. Problem solving in computing usually make up one byte. Numbers, text, images, and
involves understanding the problem, breaking it sound are all represented in binary. Data
into smaller parts, creating an algorithm, and compression reduces file size, with lossless
testing the solution. Abstraction is used to hide compression keeping all data and lossy
unnecessary details so complex problems are compression removing some data to save
easier to manage. space.
Unit 3: Algorithms & Variables Unit 4: Conditionals, Loops & Lists
An algorithm is a step-by-step process used to Conditionals allow a program to make
solve a problem. Good algorithms are clear, decisions based on whether a condition is true
correct, and finite. Efficiency refers to how or false. If-else statements control which parts
quickly an algorithm runs, especially as the size of the program run. Logical operators such as
of the input grows. Variables are used to store AND, OR, and NOT are used to combine
values in a program, and these values can conditions. Loops allow code to repeat either a
change while the program is running. Common set number of times or until a condition is met.
data types include integers, booleans, and Lists store multiple values in a single variable,
strings. and each item in a list is accessed using an
index.
Unit 5: Procedures & Program Design Unit 6: The Internet, Security & Impacts
Procedures are named sets of instructions that The internet is a global network that connects
perform specific tasks. They help reduce millions of devices. Communication on the
repetition and make programs easier to read internet relies on protocols such as IP, TCP, and
and manage. Procedures can use parameters, HTTP or HTTPS. Cybersecurity focuses on
which allow information to be passed into them. protecting data and systems from threats.
Breaking a program into smaller procedures is Common threats include malware and phishing
called modularity and makes debugging attacks. Computing has both positive and
simpler. Many programs also respond to negative impacts on society, including
events, such as button clicks or key presses. improved communication and concerns about
privacy. Increased security often involves
tradeoffs with convenience.
Unit 1: Computing & Problem Solving Unit 2: Data & Binary
Computer science focuses on using computers Data is made up of raw facts, while information
to solve problems. A computer follows is data that has been processed to have
programs, which are sets of instructions written meaning. Computers store all data using the
by humans. Because computers only do what binary system, which consists of 0s and 1s. A
they are told, instructions must be clear and single binary digit is called a bit, and eight bits
precise. Problem solving in computing usually make up one byte. Numbers, text, images, and
involves understanding the problem, breaking it sound are all represented in binary. Data
into smaller parts, creating an algorithm, and compression reduces file size, with lossless
testing the solution. Abstraction is used to hide compression keeping all data and lossy
unnecessary details so complex problems are compression removing some data to save
easier to manage. space.
Unit 3: Algorithms & Variables Unit 4: Conditionals, Loops & Lists
An algorithm is a step-by-step process used to Conditionals allow a program to make
solve a problem. Good algorithms are clear, decisions based on whether a condition is true
correct, and finite. Efficiency refers to how or false. If-else statements control which parts
quickly an algorithm runs, especially as the size of the program run. Logical operators such as
of the input grows. Variables are used to store AND, OR, and NOT are used to combine
values in a program, and these values can conditions. Loops allow code to repeat either a
change while the program is running. Common set number of times or until a condition is met.
data types include integers, booleans, and Lists store multiple values in a single variable,
strings. and each item in a list is accessed using an
index.
Unit 5: Procedures & Program Design Unit 6: The Internet, Security & Impacts
Procedures are named sets of instructions that The internet is a global network that connects
perform specific tasks. They help reduce millions of devices. Communication on the
repetition and make programs easier to read internet relies on protocols such as IP, TCP, and
and manage. Procedures can use parameters, HTTP or HTTPS. Cybersecurity focuses on
which allow information to be passed into them. protecting data and systems from threats.
Breaking a program into smaller procedures is Common threats include malware and phishing
called modularity and makes debugging attacks. Computing has both positive and
simpler. Many programs also respond to negative impacts on society, including
events, such as button clicks or key presses. improved communication and concerns about
privacy. Increased security often involves
tradeoffs with convenience.
