The document describes various functions available in the Ring standard library (stdlib.ring). It provides 37 functions organized into categories like math functions, string functions, date functions, etc. Each function includes its syntax, description and an example of its usage. Some key functions described are: evenorodd() to check if a number is even or odd, factors() to compute factors of a number, matrixmulti() to multiply matrices, and dayofweek() to get the day of the week from a date.