The lowest frequency at which the device produces audio. The lower the low-frequency response, the stronger and juicier the bass.
The highest frequency at which device produces audio. The higher the high-frequency response, the clearer and crispier the treble.
Devices with a higher sound pressure level are generally louder when supplied with any given audio source.
The driver unit is the component that produces sound in the device. Bigger drivers are more powerful and can produce better bass.