In older Broadlink RM hardware, there is only 1 step to learn RF code as the hardware contains both 315Mhz and 433Mhz receiver (and also IR receiver) separately that can perform learning simultaneously at both frequency.
In newer RM Pro, RMPro+, RMPro V3 (or similar name), there is only 1 receiver for all frequencies. The learning process has to be broken down into 2 steps.
Firstly, it tries to detect the frequency of the signal by sweeping through the full frequency range the receiver hardware can support. This is known as Sweep step.
Secondly, it decode the RF signal after locked on to the timing of 1 specific frequency from the previous step.