How do teachers detect plagiarism?

We’ve all been tempted ever to make a plagiarism in our academic work , either for lack of time, forget the quotations and footnotes , by making an honest disinterest or for some other reason unjustified work. However, plagiarism is an act that can bring serious consequences to the professional level if the teacher is aware of this fact.

The tools most used by teachers to detect extracts of plagiarism , are virtual platforms, which, through free or paid systems, provide the amount or percentage of phrases and / or words that have been copied verbatim from some source Web. Here are some of them