According to Freud’s psychoanalytic theory, repression is the involuntary, unconscious concealment of uncomfortable thoughts and desires in the unconscious. People tend to repress memories when they are too painful or difficult to deal with at the time. People do not actively know that they are hiding their memories in their subconscious, that process is called supression.
Example: A child who grew up in a violent household later has no recollection of the abuse.
Fournier, G. (2010). Repression. Psych Central. Retrieved on April 25, 2015, from http://psychcentral.com/encyclopedia/2009/repression-2/