As you want to get the details of differences between GRE and TOEFL so here is the information of the same for you:

TOEFL means Test of English as a Foreign Language and TOEFL test is conducted to determine whether or not you can speak adequate English and it is a test of minimum understanding of English and measures writing, speaking and listening abilities.

GRE Stands for Graduate Record Examinations and GRE Test is a test of intellectual preparation and consists of four sections verbal, quantitative and analytical writing ability. It is a standardized test that is an admissions requirement for many graduate schools in the United States.

GRE test is consists of 4 sections and the entire test procedure takes about 4hours. In this test there is no miminum scored was set, if you have scored above 550 for verbal and 700 for Quantitative then your scoe card was acceptable to get admission in graduate schools in the United States.

So, from both the test TOEFL is the easirer test and GRE is tough one.