What Does The Phrase (it Is All Over) Mean?

"It is all over" means it is finished/ at an end/ done. This can refer to anything which has run its course - eg the party is over, the joke is over, the day is over, the film is over etc. In practice, when you use this phrase it can sound quite dramatic, more final than just saying "It's done." Especially if you use the word "all" which suggests that the thing you're talking about is quite important.

That's why you often hear people use this phrase to describe something significant like the end of a relationship. "It's all over between us" sounds serious; whereas if someone asked you "Have you finished your dinner" and you replied "Yes, it's all over" that would sound strange and over-dramatic.

THe negative  form of this phrase is "It's not over." This is also often quite emphatic or dramatic.