Hi there 😃 Under is used when something is directly under another. Underneath is often used to say that something is covered by another thing. Beneath has the same meanings as under or underneath, but it’s a formal, literary word. Below is preferred when something is in a lower position, but in the same buliding, hill, part of the body etc. as another thing. Here's a link that will give you a small practice exercise if you'd like https://learningenglish.voanews.com/a/under-below-beneath-and-underneath/4785334.html

Hello Naike, This words are synonyms, which means they can be used interchangeable. There is no difference between them but they can be used in different contexts. For example: under and below mean something is lower or less than the other. Although underneath means the same thing as under, it can also mean something is covered by something.