If you are running a business, sometimes you simply can't run all aspects by yourself and need assistance in creating ads and running campaigns. Facebook understands this and has given all business pages the ability to add other people to your page, whether they are your employees or members from other marketing agencies.
If you are a business owner on Facebook, you'll eventually want to create ads for your business's page. To do this you need to create a Business Manager account, a function created by Facebook that allows you and if you choose to, other team or marketing members to create ads, check in on their progress and share strategies.