What does “rate” really mean?

NOTHING! I associate rate to the sticker price of an automobile. It is
just a number and does not have any value. Your rate is the number that
you and the processing company agreed to so you would sign their contract.
To prove this, perform this exercise.
Total up your Mastercard, Visa and Discover sales and multiply this total
by your rate.  Example: $10,000.00 x 1.49% = $149.00.
Your processing company deducted $548.50. This comes out to 5.48%.
Because your rate does not mean anything!