TOEFL : This exam measures your ability to speak, read, write, and understand English. It is required by many universities in English-speaking countries, such as the United States, Canada, and Australia.
IELTS : This exam is similar to the TOEFL, but is more commonly required by universities in the United Kingdom and other countries.
GRE : This exam is required by many graduate programs in the United States and other countries. It measures your verbal reasoning, quantitative reasoning, and analytical writing skills.
GMAT : This exam is required by many business schools around the world. It measures your abilities in critical thinking, analytical writing, and problem-solving.
SAT : This exam is commonly required for undergraduate admissions to universities in the United States. It measures your reading, writing, and math skills.
ACT : This exam is similar to the SAT and is also commonly required for undergraduate admissions to universities in the United States. It measures your knowledge in English, math, reading, and science.