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WalesDigital Technology

Data

6 dot points across 6 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

What is data compression, and how do lossy and lossless methods differ?

Explain the purpose of data compression and describe the difference between lossy and lossless compression, including when each is appropriate.
A focused answer to the WJEC GCSE Digital Technology content on compression, covering why files are compressed and the difference between lossy and lossless methods, with their uses and trade-offs.
9 min answer →

What are the units of digital storage, and how do you convert and calculate file sizes?

State the units used to measure data (bit, byte, KB, MB, GB, TB), convert between them, and calculate and compare file and storage sizes.
A focused answer to the WJEC GCSE Digital Technology content on measuring data, covering the units from bit to terabyte, converting between them, and calculating how many files fit on a storage device.
9 min answer →

Why do digital systems represent all data in binary, and how do bits and bytes work?

Explain why digital systems store and process all data as binary, and describe how bits, nibbles and bytes represent numbers, text and other data.
A focused answer to the WJEC GCSE Digital Technology content on binary, explaining why computers use a two-state system, how bits combine into bytes, and how binary codes represent numbers and characters.
9 min answer →

How is a digital image represented as binary, and what affects its quality and file size?

Describe how bitmap images are represented using pixels and colour depth, and explain how resolution and colour depth affect image quality and file size.
A focused answer to the WJEC GCSE Digital Technology content on representing images, covering pixels, resolution, colour depth and metadata, and how these determine image quality and file size.
10 min answer →

How is sound converted into binary, and what affects its quality and file size?

Describe how analogue sound is sampled to produce digital data, and explain how sample rate and bit depth affect sound quality and file size.
A focused answer to the WJEC GCSE Digital Technology content on representing sound, covering analogue versus digital, sampling, sample rate and bit depth, and how these affect quality and file size.
10 min answer →

What are the main types of storage media, and how do you choose the right one?

Describe solid-state, magnetic, optical and cloud storage, compare their characteristics, and choose appropriate storage for a given situation.
A focused answer to the WJEC GCSE Digital Technology content on storage media, covering solid-state, magnetic, optical and cloud storage and how to choose between them using capacity, speed, portability, cost and durability.
10 min answer →