A fiber connector is a small male plug that connects into a female fiber port. It typically has a ceramic ferrule that aligns the fiber accurately. There have been many types of fiber optic connectors manufactured through the evolution of technology. The most common types that are added to fiber optic cable in inside plant environments are LC, SC, ST, and FC. Some fiber connectors are pre-polished mechanical connectors for ease of installation or anaerobic connectors which require cleaving and polishing. The latest type of connector is a Fuse On connector. Fuse On connector eliminates the need for a splice tray. You can get most models of fiber connectors in either mechanical, Fuse On, or anaerobic.
As you can see you can have many combinations of fiber connectors such as SC/APC Fuse On. You have to be very knowledgeable about the fiber type and connector type it requires. If you have an older fiber system in your facility it may have ST connectors on OM1 or 62.5 micron fiber which will have an orange sheath on the fiber. OM1 fiber with ST connectors would need fiber patch cords with the correct connector as well. The color matters in the fiber optic world. One of the most common issues we discover in data rooms is seeing a mismatch of fiber patch cords to fiber color. We have been on many service calls where we go on-site to discover a yellow OS2 (single mode) patch cord plugged into an Aqua OM3 fiber.