Text can be stored by assigning numbers to letters, symbols, and punctuation marks using systems such as ASCII or Unicode.
Images and sound
Pictures are stored as pixels with numeric color values.
Sound is stored as samples that measure the wave at many points over time.
Compression
Lossless vs lossy
Lossless compression reduces file size without losing original data, which is helpful for documents, spreadsheets, and some image or audio formats.
Lossy compression removes some data to make files much smaller, which is common for music, video, and photos where perfect reconstruction is less important.
Devices and networks
Talking points
Programming helps devices respond to user input, automate tasks, connect to networks, and display useful information.
Computers, phones, and consoles all process data, run software, and connect to the internet, but they differ in portability, controls, and typical uses.
A LAN connects devices in a limited area like a home, school, or office, while a WAN connects devices across larger distances.
Digital Information and Devices discussion locked
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Compression examples
Describe the difference between lossy and lossless compression and give one example of when each might be used.
Lossless compression
Lossless compression keeps all the original data, so the file can be rebuilt exactly.
It is a good fit for things like documents, spreadsheets, text files, and some image formats.
Lossy compression
Lossy compression removes some data to make the file smaller.
It is often used for music, videos, and photos when a smaller file size matters more than perfect detail.