1.3.3 | STORAGE AND COMPRESSION

Topics from the Cambridge IGCSE (9-1) Computer Science 0984 syllabus 2023 - 2025.

OBJECTIVES
​1.3.3 Understand the purpose of and need for data compression

ALSO IN THIS TOPIC
1.1.1 NUMBER SYSTEMS
1.1.2 NUMBER SYSTEMS
1.1.3 NUMBER SYSTEMS 
1.1.4 NUMBER SYSTEMS
 ​1.1.5 NUMBER SYSTEMS
1.1.6 NUMBER SYSTEMS
1.2.1 TEXT, SOUND AND IMAGES
​​1.2.2 TEXT, SOUND AND IMAGES
​1.2.3 TEXT, SOUND AND IMAGES
​1.3.1 STORAGE AND COMPRESSION
​​1.3.2 STORAGE AND COMPRESSION
YOU ARE HERE | ​​1.3.3 STORAGE AND COMPRESSION
​1.3.4 STORAGE AND COMPRESSION
TOPIC 1 KEY TERMINOLOGY
TOPIC 1 ANSWERS
TOPIC 1 TEACHER RESOURCES (CIE)

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WHAT IS DATA COMPRESSION

Many files such as images, videos and even text documents can take up large amounts of memory, meaning an increased need for storage space and slower transfer speeds do to file size, this has led to the need for data compression. Data Compression is the process of making files require less memory to store.  When people talk about 'file size' they are usually referring to the memory required to store the file and not the physical size of the document or file.

There are two main methods of file compression, lossy and lossless. Each type of file compression has its benefits and disadvantages. To compress a file software such as Win Zip or is used Archive Utility Zip are used, files zipped by one software brand should be able to be uncompressed by other brands. Different file types use different methods of compression, for example compression an image will use a different algorithm to compressing a text document.

Some reasons for compression are:

✓ Compression makes the file size smaller so less space is needed to store the file
✓ Compression makes the file size smaller so files transfer faster over a network such as the internet
✓ Compression makes the file size smaller which helps with file streaming

NAVIGATION

1.1.1 NUMBER SYSTEMS | Why Computers use Binary
1.1.2 NUMBER SYSTEMS | Binary, Hex and converting between number systems 
1.1.3 NUMBER SYSTEMS | Benefits of Hex
1.1.4 NUMBER SYSTEMS | Binary Addition and Overflow
1.1.5 NUMBER SYSTEMS | Binary Shifts
1.1.6 NUMBER SYSTEMS | Negative Number Representation, Two's Complement
1.2.1 TEXT, SOUND AND IMAGES | How Computers Represent Text
1.2.2 TEXT, SOUND AND IMAGES | How Computers Represent Sound
1.2.3 TEXT, SOUND AND IMAGES | How Computers Represent Images
1.3.1 STORAGE AND COMPRESSION | How Data Storage is Measured
​1.3.2 STORAGE AND COMPRESSION | Calculating Image and Sound File Size
​1.3.3 STORAGE AND COMPRESSION | Purpose of Data Compression
​1.3.4 STORAGE AND COMPRESSION | Lossy and Lossless, how files are compressed
TOPIC 1 KEY TERMINOLOGY
TOPIC 1 ANSWERS
TOPIC 1 TEACHER RESOURCES (CIE)