As defined already, the force that produces 1 m/sec 2 acceleration on 1 kilogram mass is called as 1 Newton. This unit is recognized as SI unit. Since, forces are also measured in other types of units, a necessity arises to express all such units in equivalent to Newton unit of force.
AS stands for Associate of Science, a 2-year degree.
P.S. stands for Postscript. P.S. is an initialism (type of abbreviation which is pronounced letter by letter). It has Latin origins from Post Scriptum (after the main script).