Base Excision Repair (BER) is a cellular mechanism that corrects DNA damage caused by oxidation, deamination, or alkylation. It involves the removal of damaged or incorrect bases from the DNA strand, ensuring the genetic material remains intact and functional. The process begins with a specific enzyme called a DNA glycosylase, which identifies and removes the faulty base. This creates an abasic site, which is then processed by other enzymes, including AP endonuclease and DNA polymerase, to fill in the gap with the correct nucleotide, followed by sealing the DNA strand with DNA ligase.