I have been using smokeless tobacco on and off for years. I thought I quit numerous times but I now realize that wasn't really the case. You can say that I merely stopped using for periods of time. The difference now is that I finally quit, meaning that I am done and will not start again. I'm well over the hump.
A megabyte is one thousand times larger than a kilobyte. The prefixes mega- and kilo- are used by a metric system of counting which is based on powers of ten. Mega comes from a Greek word megas, which translates as great. In metric systems, mega- denotes one million.
Therefore 1 KB (one kilobyte) is 2 10, or 1,024, bytes; 1 MB (one megabyte) is 2 20, or 1,048,576 bytes. The choice of power-of-10 versus power-of-2 prefix multipliers can appear arbitrary.