Introduction one of the main structures of abstract, but takes it quite a bit, only 1-1,5 pages. Don't try to write a lot, your task is to interest the introductory part of the man. Try to write as understandable, but to fit in the minimum size. To place the introduction after the contents (or TOC) and to chapters in your essay.
Having dealt with the location, proceed to the main content of the introduction. It should contain the relevance of the given topic, determine the purpose of the work, specify the problem to be solved to achieve the goal, briefly describe the structure of the essay, as well as to characterize the sources used.
For the relevance in the introduction it should be noted the importance of reviewing, learning and using this process in real time. Explain the reason, so will be interesting to read the introductory part of the essay.

Putting the tasks of your essay, you will give a clear understanding of the essence of your work.

In addition, the introduction should be brief description of the chapters.
Gathering all into one small text that will be read before you start most of your work. From a well-constructed introduction will also depend on the assessment of your essay.