The General Test measures analytical writing, verbal, and quantitative skills that have been acquired over a long period of time and that are not related to any specific field of study.

The analytical writing section tests your critical thinking and analytical writing skills. It assesses your ability to articulate and support complex ideas, analyze an argument, and sustain a focused and coherent discussion. It does not assess specific content knowledge.

The verbal section measures your ability to analyze and evaluate written material and synthesize information obtained from it, to analyze relationships among component parts of sentences, to recognize relationships between words and concepts, and to reason with words in solving problems. There is a balance of passages across different subject matter areas: humanities, social sciences, and natural sciences.

The quantitative section measures your basic mathematical skills, your understanding of elementary mathematical concepts, and your ability to reason quantitatively and solve problems in a quantitative setting. There is a balance of questions requiring arithmetic, algebra, geometry, and data analysis. These are content areas usually studied in high school.

There are two kinds of taking GRE test, Paper based and Computer Bases GRE.
Structure of the Computer-Based General Test

The computer-based General Test contains four sections, one of which is an unidentified pretest section that can appear in any position in the test after the analytical writing section. Questions in the pretest section are being tested for possible use in future tests and answers will not count toward your scores. An identified research section that is not scored may also be included and this section would always appear in the final section of the test. Questions in the research section are included for the purpose of ETS research and answers will not count toward your scores.

Total testing time is up to 3 1/4 hours, not including the research section. The directions at the beginning of each section specify the total number of questions in the section and the time allowed for the section. The analytical writing section will always be first. For the Issue task, two topics will be presented and you will choose one. The Argument task does not present a choice of topics; instead, one topic will be presented. The verbal and quantitative sections may appear in any order, including an unidentified verbal or quantitative pretest section. Treat each section presented during your test as if it counts.
Typical Computer-Based GRE General Test
Section + Number of Questions + Time
Analytical Writing - 1 Issue task*- 45 min.
                            1 Argument task*- 30 min.
Verbal- 30q- 30 min.
Quantitative- 28q- 45 min.
Pretest** Varies Varies
Research*** Varies Varies

* For the Issue task, two essay topics will be presented and you will choose one. The Argument task does not present a choice of topics; instead one topic will be presented.

** An unidentified verbal or quantitative pretest section may be included and may appear in any order after the analytical writing section. It is not counted as part of your score.

*** An identified research section that is not scored may be included and it will always be at the end of the test.
Structure of the Paper-Based General Test

The paper-based GRE General Test contains five sections. In addition, one unidentified pretest section may be included and this section can appear in any position in the test after the analytical writing section. Questions in the pretest section are being tested for possible use in future tests and answers will not count toward your scores.

Total testing time is up to 3 3/4 hours. The directions at the beginning of each section specify the total number of questions in the section and the time allowed for the section. The analytical writing section will always be first. For the Issue task, two topics will be presented and you will choose one. The Argument task does not present a choice of topics; instead one topic will be presented. The verbal and quantitative sections may appear in any order, including an unidentified verbal or quantitative pretest section. Treat each section presented during your test as if it counts.
Typical Paper-Based General Test
Section + Number of Questions + Time
Analytical Writing- 1 Issue task*- 45 min.
                           1 Argument task*- 30 min.
Verbal (2 sections)- 38 per section- 30 min. per section
Quantitative (2 sections)- 30 per section- 30 min. per section
Pretest** Varies 30 min.

* For the Issue task, two essay topics will be presented and you will choose one. The Argument task does not present a choice of topics; instead, one topic will be presented.
** An unidentified verbal or quantitative pretest section may be included and may appear in any order after the analytical writing section. It is not counted as part of your score.

For more info you can visit the official GRE web site at www.gre.org