What does it mean?
DSP means Digital Signal Processing. Software calculates changes to incoming audio samples and produces samples for the output. In Pedal Rigs, a signal path can contain EQ, compression, drive, an amp, a cabinet, synthesis, delay and reverb. DSP here describes processing in the app, rather than a promise of a dedicated hardware chip. Sample rate, buffer size, drivers and effect algorithms influence processing load and latency. Buffer size alone does not measure the full hardware round trip.
ExampleA guitar enters through an audio interface. Compression shapes its dynamics, the amp and cabinet shape its character, and delay and reverb add space before the output.