Hop bursting concentrates most or all of a beer's total hop charge into the last 5-15 minutes of the boil (or into whirlpool and dry-hop additions beyond that), rather than spreading hop mass across a traditional 60-minute bittering charge plus smaller late additions — a deliberate strategy to maximize aroma and flavor character relative to bitterness.
Why this produces a different beer than the same hop weight boiled longer
Because utilization rises steeply over a boil's first 20-30 minutes and then levels off, moving hop mass from an early, long-boiled addition to a late, short-boiled one genuinely reduces the total bitterness that same weight of hops would otherwise contribute — hop bursting trades some of that bitterness away deliberately, in exchange for considerably more of the fresh, volatile aroma compounds a long boil would otherwise drive off.
The technique underneath most modern hop-forward American styles
Hop bursting, whirlpool hopping, and dry hopping all work from the same underlying principle — less heat exposure preserves more aroma at the cost of less bitterness — and modern hop-forward styles, particularly New England IPA, typically combine all three techniques together rather than relying on any single one to carry the beer's full aroma-forward character, since each captures a slightly different part of the aroma spectrum.