ASCII - American Standard Code for Information Interchange, is a character encoding standard for electronic communication
BCD - (Binary Coded Decimal) representing each denary digit with 4 bits
Bitmap - (raster graphics) an image where each pixel is encoded with bits
File header - info on image format, palette, dimensions, etc
Metadata - info on author, date or location of shot / creation, etc
Image resolution - the variable number of pixels in the image, e.g: 1920 x 1080
Screen resolution - the fixed number of pixels on the display
Free software - can be modified and distributed without cost or permission
Freeware - can be used without cost, but cannot be modified or distributed
Shareware - a free trial or limited version of software; users encouraged to modify and distribute copies at no cost.
Adware - malware (malicious software) which presents unwanted advertisements to the user.