... unless you intend to communicate what the terms actually mean.
I see this term bandied about a lot in the forum. Unfortunately, it's almost always used as an fancy synonym for the simpler, "use." A use case is a formal structure (i.e. model) that defines how a system and its users interact to perform a particular task or accomplish a particular goal. A typical application is a diagram or flow chart showing how users interact with a website to reach the information they're after. So it's less correct to say, "This new-fangled processor can be applied to many new use cases," when you mean, "This new-fangled processor has many new uses."
This term is almost never used in the first post of a thread. It's almost always used as a high-brow way to respond critically to something someone else has posted. The dictionary definition is: combine (two or more texts, ideas, etc.) into one. It's not a synonym for "confuse," which is how it's often used. As an example, avoid saying, "You're conflating threads and processes," when you mean, "You're confusing threads with processes." Yeah, I know: the first seems less confrontational which, I suspect, is why it gets overused.
So the lesson is this: keep it simple, and be direct, by avoiding unnecessary jargon.
Perfection is achieved not when there is nothing more to add, but when there is nothing left to take away. -Antoine de Saint-Exupery