Reading Specs on Motor Drivers
1) Logic voltage is the voltage used for the control (PWM) inputs.  Drive voltage is the voltage used to power the motor itself.

2) Number of channels:  "Can drive two bidirectional DC motor or a four line two phase stepper motor".  So, each channel can drive one DC motor. (Stepper motors are more complicated,.

3) Max continuous current per channel:  This one is pretty self explanatory, so I'm not sure what you're having trouble understanding.  But this is the maximum current that the driver can continually provide to the motor (if the motor draws more current than this, the driver might overheat)