a sequential tranny (which doesn't exist for honda, unless you want to pay $20,000 or more) is a tranny like f1 cars use, and hell a motor cycle is probably a better example. one click up, and you go one gear. if you want to drop 2 gears, you have to press it down twice. basically, its an inline shifter, some are clutchless, some aren't, so on and so forth..
1-2-3-4-5-6
if you wanted to go from 6th to 3rd for a pass, youd have to hit 5th then 4th to get to 3rd, instead of just moving directly to 3rd