What are the different types of fast adders?

Fast adders are designed to improve the speed of addition in digital circuits. The main types include Ripple Carry Adders (RCA), which are simple but slow due to carry propagation; Carry Lookahead Adders (CLA), which reduce delay by calculating carry bits in advance; and Carry Select Adders (CSA), which use multiple adder circuits to quickly resolve carries based on anticipated values. Other types include Carry Skip Adders (CKA) and Brent–Kung Adders, both of which aim to balance speed and resource usage.