Lasers emit a narrow spectrum

It emits a very narrow range of frequencies (small linewidth), which for many purposes can be considered a single frequency.

It does however have a small range of frequencies. The smaller the range, the better the laser quality.

electronics.stackexchange.com/questions/477264/spectrum-of-leds claims cheap LEDs have 20 nm width at 50% from peak, and cheap lasers can be 1 nm or much less