Retention, in psychological or educational usage, refers to a person's ability to retain and use information. This ability is imperative in learning new skill. The ability to retain information depends on several factors such as basic intelligence and familiarity with the basic subject matter.
For instance, if a person encounters new information regarding their career field their ability to retain the new information should be high. However, if a person encounters information about a field that is totally new to them retention of the new material is not as likely.