It all means that many people are together for collective activities. The differences are as follows:

1, "gathering" usually refers to a relatively random gathering without a specific purpose, emphasizing the communication and interaction between people. For example, "some of our friends go to the park for a party on weekends."

2. "Party" usually refers to an organized, purposeful, celebratory or commemorative gathering, emphasizing collective actions and activities. For example, "We are going to have a birthday party in the restaurant."

3. "Gathering" is more casual and relaxed, which can be a small gathering between friends or a gathering between neighbors; A "party" is more formal and organized, and needs to be arranged in advance, usually for a specific purpose.