The time value of money is one of the basic concepts of finance. Time value of money is the change in consumption power of money over time. $100 today can consume more than $100 in 5 years. It also takes into account some risk. $100 today is a sure thing and can be enjoyed now. In 5 years that money could be worthless or not returned to the investor. This is where the interest rate inherent in TVM comes from.
A hundred dollars invested today at 5% per year interest rate will yield
A hundred dollars 1 year from now at 5% interest rate is today worth:
See also: Time preference theory of interest