The base-2 logarithm, denoted as log₂, is a mathematical function that determines how many times the number 2 must be multiplied together to reach a given value. For example, log₂(8) equals 3 because 2 multiplied by itself three times (2 × 2 × 2) equals 8. This logarithm is particularly useful in computer science, where binary systems are prevalent. In practical terms, the base-2 logarithm helps in analyzing algorithms, especially in measuring their efficiency. It is often used to express the complexity of sorting and searching algorithms, such as binary search, which operates in logarithmic time, making it much faster than linear approaches for large datasets.