My classmates invited me to hold a wedding banquet, didn't they wrap the invitation with a red envelope?

That classmate invited you to a wedding banquet, but he didn't give you an invitation. This is a question of the form of invitation. Inviting others to a happy event is a common way in ancient times, also known as an invitation, and the format of the invitation is very particular, and it needs to be written by someone. However, with the development of society, the way of inviting guests has changed. Invitation is no longer the main way, but telephone invitation, unit invitation, face-to-face signing and so on. Face-to-face invitation is more formal and grand than other ways. Often when inviting leaders and elders, the host needs to invite them in person. Your classmates invite you to the wedding banquet in various forms. As classmates, you don't have to stick to the formality. As long as you are invited, you must give gifts, unless the host declares in advance that you just invite everyone to get together and don't accept gifts. Even so, it is generally polite.