I need to understand ratio plz help

If your looking for basically the definition of ratio it means, lets say we have 2 can of milks, and 3 cans of cookies, if it asks find the ratio of milks first then cans it is 2:3, or if it asks find the ratio of cans of milk to cookies, which is 3:2 or part to whole which means 3+2 or 2+3= 5 is whole and if they say part would be milk then 2:5 or if its cans of cookies to whole its, 3:5. I hope this helps ask me anything that you didn’t understand!