Thanks in part to its Latin heritage, in Spanish the meanings of many words can be changed through the use of prefixes. Many of them are likely to seem familiar to you: Among them is the subject of our newest lesson, on the prefix des-, which also can take the form of de- and dis-. They're used much the same as "de-" and "dis-" in English.

Comments
I have noticed that even when it not translated that way it implies negation for example descansar literally means to untire or as we would say rest.