In programming language, "oops" most likely means that you made a mistake, possibly causing an error.
OOP is object oriented programming. It is the idea of using "objects" to represent something with properties (think characteristics like size, color, etc.) and methods (think actions like move, print, etc.). These objects can then have instances of them created to represent a specific version of that object. Objects provide a way to reuse code in an organized way.
Those are just the very basic ideas of object oriented programming, there are many other ideas such as inheritance, encapsulation, and polymorphism.