GRE (Graduate Record Examination) is an exam in the United States, as well as in
other countries (Canada, Australia, etc.), which is important to admit for graduate
degrees, postgraduate degrees, or business schools.
This test is held in more than 1000 testing centers in more than 160 countries
around the world. Examination is managed by the Educational Testing Service
(ETS).
The GRE exam is divided into two groups:

GRE General test (Overall test)
GRE Subject test (Special subject test)
GRE General Test - Many universities in the world require this test.
GRE Overall test consists of 3 parts:

• Verbal Reasoning - This section consists of two parts that each has 20 questions. Each part is given 30 minutes. Here some of the reading, understanding, and analyzing skills are checked. It is estimated according to the130-170 score system.
• Quantitative Reasoning - This section consists of two parts each with 20 questions. It takes about 30 minutes for each part. Here are the questions and tasks in math, geometry, mathematical logic.
• Analytical Writing - This unit has 2 parts and needs to finish each part within 30 minutes. These parts consist of essays. It is estimated according to 0-6 score system. Overall, GRE takes 4 hours. This exam is held on average every 2 months. GRE Subject test - This exam is for students who specialize in special professions. The test covers 8 subjects: Biochemistry, Biology, Chemistry, Computational Science, English Literature, Mathematics, Physics and Psychology. Registration for the GRE exam is available online or via e-mail. You can sign up to gre.org for exam dates, latest registration history, and other information. The GRE certificate is valid for 5 years.