You wouldn't apply for a product buyer/sales job would you?
Yet both involve talking on the phone to people in faintly related tasks. Yet they're two fundamentally different jobs. One is purchasing from people the other is selling to people.
Likewise, you shouldn't apply for social media/online community manager jobs. They are two very different roles (believe me, I've done both). You can't do them both at the same time, certainly not very well.
Social media managers are usually responsible for a handful online communication channels. You might develop a strategy, send out messages and reply to people and try to grow the total audience you're trying to reach. It's you talking with members.
Online community managers are usually responsible for a group of people who talk to each other around a shared interest. You bring in others with that interest, initiate discussions, activities and create content about members with that interest and further develop their sense of community. It's members talking to each other.
If you're an employer, decide which you want and hire someone specifically for that. If you're looking for an online communications job, decide which you want to do and look for that.