What is special about f and i keys on a standard keyboard

What are compression artifacts? 1) visible defects in the picture caused by the nature of the compression algorithm. 2) numbers that tell a web server how much to compress a picture for faster transmission. 3) invisible defects in the picture preserved by lossless compression. 4) numbers that tell a photo editing program how much to compress a picture for faster transmission.

Which part of the cpu accepts data?

Idon’t understand the double8 coding problem. it is java