The author copies important portions of wording straight from a single source, without modification and does not cite the source. For example, if the student copies a sentence "Einstein said exactly this-time is relative to the entities experiencing it. One man's second can be another woman's forty years. Einstein gives an example of a man who travels at very close to the speed of light to a star-say twenty light years away." from that passage without any alteration and no citation, then it would be called "Replication."