Q:

Infinite word size abstraction

I was reading the java doc of BigInteger, they mentioned "infinite word size abstraction" more than one places. what are they referring to?
https://docs.oracle.com/javase/7/docs/api/java/math/BigInteger.html

A:

They are referring to word as  processing unit for a computer processor.
https://en.wikipedia.org/wiki/Word_(computer_architecture)
The word size is normally a small number like 32 or 64 bits for a given processor, but BigInteger provides an abstraction for infinite word size.

