AP Computer Science Principles Vocabulary
Q AND A UPDATED
Algorithm
At its core, an algorithm is really just a generalized, conceptual solution to a problem that can later be
implemented in some real-world form like a computer program.
Application Program Interface
Application program interface (API) is a set of routines, protocols, and tools for constructing software
applications. An API specifies how software components should interact. In addition, APIs are used when
programming graphical user interface (GUI) components.
Binary
A numeric system of base 2 that only uses combinations of the digits zero and one; this is used in one of
the lowest levels of abstraction. Computers operate in binary, as they store data and perform
calculations using only zeros and ones. While a single binary digit can be used to represent True (1) or
False (0) in Boolean logic, multiple binary digits can be used in conjunction to store large numbers and
perform complex functions. Computers translate between binary and what you actually work with such
as numbers and text.
Binary Search
A search algorithm that locates the position of a target value within a sorted array by repeatedly dividing
the search interval in half; can only be used when the list is sorted. Because of its divide-and-conquer
,approach, the amount of work required to find an item grows much more slowly with Binary Search
than with Sequential Search. In fact, with this logarithmic behavior
Boolean Function*
Any function based on the operations AND, OR, and NOT, and whose elements are from the domain of
Boolean algebra. A function whose arguments, as well as the function itself, assume values from a two-
element set (usually {0,1})
Central Processing Unit
CPU, or processor, is the brains of the computer where most calculations take place. Contains the
circuitry necessary to interpret and execute program instructions.
Computational Artifact
Something created by a human using a computer and can be, but is not limited to, a program, an image,
an audio, a video, a presentation, or web page file
Cryptography
The science of coding and decoding messages in order to keep them secure. Coding takes place using a
key that ideally is known only by the sender and intended recipient of the message.
Floating Point Numbers
As the name implies, floating point numbers are numbers that contain floating decimal points. Examples
include, the numbers 5.5, 0.001, and -2,345.6789. Numbers without decimal places are called integers.
Computers recognize real numbers that contain fractions as floating point numbers.
,Hexadecimal
Hexadecimal describes a base-16 number system. That is, it describes a numbering system containing 16
sequential numbers as base units (including 0) before adding a new position for the next number. The
hexadecimal numbers are 0-9 and then use the letters A-F. Used to represent digital data because it
utilizes fewer digits than binary.
Integers
An integer is a whole number (not a fraction) that can be positive, negative, or zero. In computer
science, an integer is a datum of integral data type, a data type that represents some finite subset of the
mathematical integers. Integral data types may be of different sizes and may or may not be allowed to
contain negative values.
Iterations
Iteration is the repetition of part of an algorithm until a condition is met or for a specified number of
times. This is often called a 'loop'. Recursive functions repeatedly execute themselves as part of their
operation. Upon completing all instructions and resetting to the first one iteration has been completed.
Libraries
In computer science, a library is a collection of non-volatile resources that a program can use often to
develop software. Libraries are particularly useful for storing frequently used routines because you do
not need to explicitly link them to every program that uses them. The linker automatically looks in
libraries for routines that it does not find elsewhere. Resources which may be found in libraries include
data, documentation, message templates, pre-written code, classes, or values.
, Linear/Sequential Search
A process that checks every element in the list sequentially until the desired element is found or all
elements have been searched. Can be used in any type of list. Has linear performance.
Lossless Data Compression
With lossless compression, every single bit of data that was originally in the file remains after the file is
uncompressed. All of the information is completely restored. This is generally the technique of choice
for text or spreadsheet files, where the loss of words or financial data could pose a problem. PNG is an
image format that provides lossless compression.
Lossy Data Compression
Lossy compression reduces a file by permanently eliminating certain information, especially redundant
information. When the file is uncompressed, only a part of the original information is still there
(although the user may not notice it). Lossy compression is generally used for video and sound, where a
certain amount of information loss will not be detected by most users. JPEG provides lossy compression.
Metadata
Metadata is data that describes other data. Metadata summarizes basic information about data, which
can make finding and working with particular instances of data easier. It provides information
concerning an item's content such as image resolution and size.
Parameters*
In computer programming, a parameter or "argument" is a value that is passed into a function. Most
modern programming languages allow functions to have multiple parameters. While the syntax of a
function declaration varies between programming languages, a typical function with two parameters
may look something like this:
Q AND A UPDATED
Algorithm
At its core, an algorithm is really just a generalized, conceptual solution to a problem that can later be
implemented in some real-world form like a computer program.
Application Program Interface
Application program interface (API) is a set of routines, protocols, and tools for constructing software
applications. An API specifies how software components should interact. In addition, APIs are used when
programming graphical user interface (GUI) components.
Binary
A numeric system of base 2 that only uses combinations of the digits zero and one; this is used in one of
the lowest levels of abstraction. Computers operate in binary, as they store data and perform
calculations using only zeros and ones. While a single binary digit can be used to represent True (1) or
False (0) in Boolean logic, multiple binary digits can be used in conjunction to store large numbers and
perform complex functions. Computers translate between binary and what you actually work with such
as numbers and text.
Binary Search
A search algorithm that locates the position of a target value within a sorted array by repeatedly dividing
the search interval in half; can only be used when the list is sorted. Because of its divide-and-conquer
,approach, the amount of work required to find an item grows much more slowly with Binary Search
than with Sequential Search. In fact, with this logarithmic behavior
Boolean Function*
Any function based on the operations AND, OR, and NOT, and whose elements are from the domain of
Boolean algebra. A function whose arguments, as well as the function itself, assume values from a two-
element set (usually {0,1})
Central Processing Unit
CPU, or processor, is the brains of the computer where most calculations take place. Contains the
circuitry necessary to interpret and execute program instructions.
Computational Artifact
Something created by a human using a computer and can be, but is not limited to, a program, an image,
an audio, a video, a presentation, or web page file
Cryptography
The science of coding and decoding messages in order to keep them secure. Coding takes place using a
key that ideally is known only by the sender and intended recipient of the message.
Floating Point Numbers
As the name implies, floating point numbers are numbers that contain floating decimal points. Examples
include, the numbers 5.5, 0.001, and -2,345.6789. Numbers without decimal places are called integers.
Computers recognize real numbers that contain fractions as floating point numbers.
,Hexadecimal
Hexadecimal describes a base-16 number system. That is, it describes a numbering system containing 16
sequential numbers as base units (including 0) before adding a new position for the next number. The
hexadecimal numbers are 0-9 and then use the letters A-F. Used to represent digital data because it
utilizes fewer digits than binary.
Integers
An integer is a whole number (not a fraction) that can be positive, negative, or zero. In computer
science, an integer is a datum of integral data type, a data type that represents some finite subset of the
mathematical integers. Integral data types may be of different sizes and may or may not be allowed to
contain negative values.
Iterations
Iteration is the repetition of part of an algorithm until a condition is met or for a specified number of
times. This is often called a 'loop'. Recursive functions repeatedly execute themselves as part of their
operation. Upon completing all instructions and resetting to the first one iteration has been completed.
Libraries
In computer science, a library is a collection of non-volatile resources that a program can use often to
develop software. Libraries are particularly useful for storing frequently used routines because you do
not need to explicitly link them to every program that uses them. The linker automatically looks in
libraries for routines that it does not find elsewhere. Resources which may be found in libraries include
data, documentation, message templates, pre-written code, classes, or values.
, Linear/Sequential Search
A process that checks every element in the list sequentially until the desired element is found or all
elements have been searched. Can be used in any type of list. Has linear performance.
Lossless Data Compression
With lossless compression, every single bit of data that was originally in the file remains after the file is
uncompressed. All of the information is completely restored. This is generally the technique of choice
for text or spreadsheet files, where the loss of words or financial data could pose a problem. PNG is an
image format that provides lossless compression.
Lossy Data Compression
Lossy compression reduces a file by permanently eliminating certain information, especially redundant
information. When the file is uncompressed, only a part of the original information is still there
(although the user may not notice it). Lossy compression is generally used for video and sound, where a
certain amount of information loss will not be detected by most users. JPEG provides lossy compression.
Metadata
Metadata is data that describes other data. Metadata summarizes basic information about data, which
can make finding and working with particular instances of data easier. It provides information
concerning an item's content such as image resolution and size.
Parameters*
In computer programming, a parameter or "argument" is a value that is passed into a function. Most
modern programming languages allow functions to have multiple parameters. While the syntax of a
function declaration varies between programming languages, a typical function with two parameters
may look something like this:
