The word 좀 is well known (to people who've learned it already) as a more conversational and slightly less formal version of 조금. It's commonly used in speaking, and is fine for using in almost any level of speech.
However, 좀 is also useful to make a sentence sound softer - this is especially useful when making a command that you want to sound a little bit more friendly.
And that's not all. Adding 좀 to your sentences can also make them sound a little more natural - like a native speaker. In this video I explain how you can add it to your sentences in order to 좀 improve your Korean.
One word to make your Korean more natural | Korean FAQ