Here's a short story:

In signal processing, data compression, source coding, or bit-rate reduction involves encoding information using fewer bits than the original representation. Compression can be either lossy or lossless. Lossless compression reduces bits by identifying and eliminating statistical redundancy. No information is lost in lossless compression. Lossy compression reduces bits by identifying unnecessary information and removing it. The process of reducing the size of a data file is referred to as data compression. In the context of data transmission, it is called source coding (encoding done at the source of the data before it is stored or transmitted) in opposition to channel coding. 

Compression is useful because it helps reduce resource usage, such as data storage space or transmission capacity. Because compressed data must be decompressed to use, this extra processing imposes computational or other costs through decompression; this situation is far from being a free lunch. Data compression is subject to a space–time complexity trade-off. For instance, a compression scheme for video may require expensive hardware for the video to be decompressed fast enough to be viewed as it is being decompressed, and the option to decompress the video in full before watching it may be inconvenient or require additional storage. The design of data compression schemes involves trade-offs among various factors, including the degree of compression, the amount of distortion introduced (when using lossy data compression), and the computational resources required to compress and decompress the data. (End of story)

Provide your best guess for the following question. Give ONLY the guess, no other words or explanation.

For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>

Here are a few examples of questions and answers:

Question: Why is compression Useful?
Guess: it helps reduce resource usage

Question: What are the type of resource usage
Guess: data storage space or transmission capacity

Question: What is the use for this space?
Guess: SO as o compress data?

Question: What is the example of the situation for the compressed data?
Guess: compression scheme for video

Question: What utilized encoding information?
Guess: data compression, source coding, or bit-rate reduction

Question: What is the name of the process at which this is used.
Guess: signal processing

Question: What are the two varieties of compression?
Guess: lossy or lossless

Question: What differentiate the Lossy?
Guess: Lossy compression reduces bits by identifying unnecessary information and removing it

Now answer the following question in the same format.

Question: What is data compression called?

reducing the size of a data file