Global alignment refers to the process of arranging sequences from different organisms or species to identify similarities and differences. This technique is commonly used in bioinformatics to compare DNA, RNA, or protein sequences, helping researchers understand evolutionary relationships and functional similarities. The goal of global alignment is to achieve the best possible match across the entire length of the sequences being compared. Algorithms like Needleman-Wunsch are often employed to optimize this alignment, ensuring that gaps and mismatches are minimized while maximizing the overall alignment score.