The Boyer-Moore algorithm is an efficient string-searching algorithm for finding a substring (pattern) within a main string (text). Developed by Robert S. Boyer and J Strother Moore in 1977, it optimizes pattern matching by utilizing two key heuristics: the Bad Character Rule and the Good Suffix Rule.

**Bad Character Rule**: When a mismatch occurs, the algorithm shifts the pattern to align the bad character in the text with its last occurrence in the pattern. If the bad character is not in the pattern, the pattern is shifted past the bad character.

**Good Suffix Rule**: Upon a mismatch, this rule shifts the pattern to align the longest suffix of the matched portion with another occurrence of this suffix within the pattern. If no such suffix exists, the pattern is shifted entirely past the mismatched character.

The algorithm starts comparing from the end of the pattern, allowing it to skip large sections of text, especially when mismatches are frequent. Preprocessing the pattern to create bad character and good suffix tables helps determine optimal shifts during the search, reducing the number of comparisons.

For example, searching for “NEEDLE” in “FINDINAHAYSTACKNEEDLEINA” involves comparing from the end of “NEEDLE”, using the heuristics to shift the pattern efficiently, leading to faster pattern matching compared to checking each character sequentially.