What is object-oriented programming and how does it differ from functional programming?
Object-Oriented Programming (OOP) is a programming paradigm that models data as objects, each of which can have attributes and behaviors. Classes define objects and their behavior, and objects interact with each other through methods. OOP emphasizes encapsulation, inheritance, and polymorphism.

Functional Programming (FP) is a programming paradigm that emphasizes the use of functions to transform data. Functions are treated as first-class citizens, and the goal is to write pure functions that have no side effects and are deterministic. FP emphasizes immutability, recursion, and the avoidance of shared state.

In OOP, the primary unit of code reuse is the object and its behavior, while in FP, it is the function. OOP programs tend to be organized around objects that model real-world entities, while FP programs are organized around the transformations of data. OOP often employs a more imperative style, while FP uses a more declarative style.
I'm trying to build an app for simulating protein-protein interactions in real-time. Should I use OOP or functional programming for this project, or is their another approach that would work even better?
Opinions differ on whether one should use OOP or functional programming and when. Here are some things you may want to consider when deciding which might be more suitable for your project.

1. Many programming languages favor one paradigm over the other. Java, for example, strongly favors an object oriented style. If you already have a certain language or library you plan on using, it may be best to use the paradigm which is most idiomatic in that language.
2. Object oriented programming is more popular. If you plan on working with other people, it may be easier to find people to work with if your project uses an object oriented style.
3. Functional programs deal with immutable data, which makes it easier to write parallelized code. Parallelized code can make a big difference in runtime depending on the program and hardware it's running on.
4. It's easier to write tests and debug code in functional programs. The output of a function depends only on its input, not some internal persistent state, so there's much less to think about when ensuring that it behaves correctly. Programmers spend more time writing tests and debugging than writing the program itself, so this can be a big time saver.
5. It's also worth noting that some languages, such as Rust, are considered to be multi-paradigm and support both styles. If using one of these languages, you don't need to commit to one style or the other for the entire project but can instead switch between them as you deal with sub-problems that you think would be best addressed with one or the other.