A microphone’s polar pattern is the 3-dimensional space surrounding the capsule where it is most sensitive to sound. There are quite a few different patterns but here are 3 of the most popular.
Omnidirectional – The omnidirectional pattern allows picking sound from all directions. This is a great mic for choirs or any situation you are not in a noisy environment and want 360-degree sound coverage.
Cardioid: Cardioid microphones have a picking pattern that is shaped in the form of a heart. They pick up most of the sound from the front side, within the range of 120 degrees. The sides of a cardioid microphone are less sensitive, while sounds coming from the rear are completely inaudible. Because of the rear cancelation this is a very popular pattern and can be used for micing instruments, guitar amps, drums, and vocal
Super cardioid: Supercardioid polar pattern is narrower than a typical cardioid and allows a higher level of cancellation. Such microphones are thus used for a more focused recording and particularly for the reinforcement of live sound. The use of supercardioids also allows achieving a better isolation while minimizing the bleed between two nearby sound sources, such as a singer and his own guitar or background vocals in front of a drum set.