MPEG-1 or MPEG-2 Audio Layer III, more commonly referred to as MP3, is an audio coding format for digital audio which uses a form of lossy data compression. It is a common audio format for consumer audio streaming or storage, as well as a de facto standard of digital audio compression for the transfer and playback of music on most digital audio players. 

The use of lossy compression is designed to greatly reduce the amount of data required to represent the audio recording and still sound like a faithful reproduction of the original uncompressed audio for most listeners. An MP3 file that is created using the setting of 128 kbit/s will result in a file that is about 1/11 the size of the CD file created from the original audio source (44,100 samples per second × 16 bits per sample × 2 channels = 1,411,200 bit/s; MP3 compressed at 128 kbit/s: 128,000 bit/s [1 k = 1,000, not 1024, because it is a bit rate]. Ratio: 1,411,200/128,000 = 11.025). An MP3 file can also be constructed at higher or lower bit rates, with higher or lower resulting quality.
Is MP3 commonly used?
What is it used for?
What is its full name?
Is it used for analog audio?
What's the purpose of compression?
Should it sound different?
How much smaller is an MP3 file than a CD?
Could it be smaller than that?
What would happen if it was smaller?
And if it were higher, what could happen?
Yes
It is a common audio format
consumer audio streaming or storage
consumer audio streaming or storage
MPEG-1 or MPEG-2 Audio Layer III
MPEG-1 or MPEG-2 Audio Layer III
No
 It is a common audio format for consumer audio streaming or storage
reduce the amount of data required
The use of lossy compression is designed to greatly reduce the amount of data required
No
sound like a faithful reproduction
about 1/11 the size
about 1/11 the size
Yes
An MP3 file can also be constructed at higher or lower bit rates, with higher or lower resulting quality
lower resulting quality
lower resulting quality.
higher resulting quality
higher or lower resulting quality