Sequencing depth, also known as coverage, refers to the number of times a particular base or region in the genome is sequenced during an experiment. It is typically measured as "X-fold coverage" (e.g., 30X), indicating the average number of reads covering each base. High sequencing depth provides more reliable data, reducing the likelihood of random errors and increasing the confidence in variant calls. However, deep sequencing is more costly and time-consuming. Sequencing depth is a critical parameter for ensuring the accuracy and completeness of variant detection, particularly in complex regions of the genome.