Probably showing my ignorance here but ...
So far i've only used what i'd call "period" data (i.e. 1min and 1hr etc) which is OHLC and volume (don't get the open interest thing though). I also get Level II data where you get the bid/ask prices from players together with volumes each player is offering at that price. I think i also get Level I data which is the inside bid/ask (and volume?), but i don't get "tick data" which only seems to have a single price value (and volume). Is that the bid or ask?
So far i've only used what i'd call "period" data (i.e. 1min and 1hr etc) which is OHLC and volume (don't get the open interest thing though). I also get Level II data where you get the bid/ask prices from players together with volumes each player is offering at that price. I think i also get Level I data which is the inside bid/ask (and volume?), but i don't get "tick data" which only seems to have a single price value (and volume). Is that the bid or ask?