Formal:
* You (plural) - This is the most common and versatile way to address a group of people formally.
* You all - This is another formal way to address a group, emphasizing that you are referring to all of them.
* Ladies and gentlemen - This is a formal and polite way to address a group, particularly in a public setting.
Informal:
* You guys - This is a common informal way to address a group, but it can be considered slightly inappropriate in formal settings.
* Y'all - This is a regional dialectal term common in the Southern United States, and can be considered informal or even slang.
Examples:
* Formal: "You are all invited to the party."
* Informal: "You guys want to go to the movies?"
* Formal: "Ladies and gentlemen, please take your seats."
* Informal: "Y'all ready to eat?"
It's important to choose the appropriate term based on the context and your relationship with the people you are addressing.