Generally speaking, remediation is the act of providing a remedy.
Remediation and New MediaEdit
According to their book Remediation: Understanding New Media by J. David Bolter and Richard A. Grusin, remediation is a defining characteristic of new digital media because digital media is constantly remediating its predecessors (television, radio, print journalism and other forms of old media).
Remediation can be complete or visible. A film based on a book is remediating the printed story. The film may not provide any reference to the original medium or acknowledgement that it is an adaptation. By attempting to absorb the old medium entirely, the new medium presents itself without any connection to its original source. On the other hand, a medium such as a movie clip can be torn out of context and inserted into a new medium such as music. Bolter and Grusin describe this as visible remediation because, "The work becomes a mosaic in which we are simultaneously aware of the individual pieces' and their new, inappropriate setting." .... 
The Double-logic of remediationEdit
Although our culture wants to multiply its media it also wants to erase all traces of mediation. For example, a typical webiste may be hypermediated, offering photographs and streaming video. These media mediate between the viewer and the meaning of the photographs and video. The viewer does not want mediation, an intervening agency, but instead the wants immediacy, a way to get beyond mediation.
The Process of RemediationEdit
According to Bolter and Grusin, Media are continually commenting on, reproducing, and replacing each other. This process is integral to media.. Media constantly interacts with other media by reproducing and replacing and making other changes. New Media constantly justifies itself by remediating old media.
Remediation and RealityEdit
Because media intervenes, or mediates between viewers and what is represented, meaning is not immediate. In order to receive the meaning immediately, the viewer can ignore the presence of the medium and the act of mediation or by diminishing the medium's representational function. When painters of modern art chose everyday objects, like soup cans to represent, they removed mediation. The viewers received the meaning immediately because the object came from their "real" world; it is not representative of something abstract.