Many people think that the IQ test tells about a person's intelligence, but it only measures the ability to understand abstract logic, and does not measure the amount of knowledge a person has.

One of the misunderstandings about these tests is that people think that it measures the level of intelligence, but in fact it measures the ability to understand abstract logic, while emotional and practical intelligence and long-term memory are not included, warns Dr. Gavin Evans. He adds that he is not automatically against these tests, he considers them useful in measuring the ability to master mathematics, science and IT technology, because they measure similar traits that the IQ test measures.
Reference: https://n1info.hr/magazin/lifestyle/a507384-strucnjaci-sto-zapravo-test-inteligencije-otkriva-o-covjeku/

Intelligence testing is more appropriate if you want to test someone's ability to understand abstract logic. I believe that these types of tests are suitable when enrolling in school or interviewing for a job. In this way, one can check how easily a person understands abstract logic. It should be noted that such tests are not a reflection of intelligence. People who take tests often can improve their results.
Knowledge tests give us insight into how much knowledge a person possesses in a certain area (foreign languages, history, geography). A knowledge test can also be a test of general knowledge. We can see this type of tests on television in the form of various quizzes. A knowledge test can be done when enrolling in school if it is assumed that the child has a large amount of knowledge and they want to check if he can possibly move to a higher grade.