What does 'no deductible' mean?

I have no clue what this means!! Pls explain... Example for dental plan: Basic Care 20%, no deductible. What's no deductible, and does this mean I only pay 20% of the bill or what?
--------------------
A deductible is an amount you have to pay before the insurance kicks in and starts paying it's portion. You could still have a co pay or a coinsurance (the difference being a copay is a flat amount, for instance $10 for each office visit, while coinsurance is a percentage, 10 percent of the bill), so you might want to ask your insurance company if it isn't clear.
Source