Yes, the statement is right (at least for most part). Let's consider a simple example. Let's assume you had two choices:
1.) take $1 today or 2.) take $1 next year. Taking $1 today is a better option because you don't have to deal with what could happen in the future. The $1 might not be there in the future. One lesson from this example is that money received today has little to no risk as compared to the same amount received in the future.
Another reason while money has more worth today than money received sometimes in the future is because of inflation. Most items prices increase every year. e.g. college tuition, milk, etc.