The SC and ST connectors refer to different types of fiber optic connectors. The ST connector is round and resembles a BNC connector, utilizing a push-and-twist mechanism for connection. In contrast, the SC connector is rectangular and designed for a slide-in slot connection. Fiber optic cables fall into two main categories: single-mode fibers, which have small cores (approximately 9 microns in diameter) and transmit infrared laser light at wavelengths of 1,300 to 1,550 nanometers, and multi-mode fibers, which feature larger cores (about 62.5 microns in diameter) and transmit infrared light from LEDs at wavelengths of 850 to 1,300 nanometers.