HCF is a term that is commonly used in math. This stands for Highest Common Factor, and this is something that you look for when you need to check out the different factors of two numbers that are being compared. For example, the highest common factor of 75 and 105 is 15.
If you would check the different factors of these two numbers, you will get 1, 3, 5, and 15. 15 is obviously the biggest number out of all the rest. Aside from the HCF, people may also want to search for the LCM or least common multiple. You need to list down the various factors of these numbers and put a circle on the common ones until you find the highest factors available.