Bank means the MSB (most significant byte), also called controller 0

Sub-Bank means LSB (least significant byte), also called controller 32

Most keyboards / sound modules utilize one or both of these bank-select messages to select banks. Some can recognize either. Check with your synth's manual to find out what method is required.

* Please note, some keyboards / sound modules work with MIDI on a scale of 0-127, some are 1-128, so an offset of one may be needed to achieve the correct bank.