IOS 5 "Home Button" from Sleep Behavior

can anyone help me with an explanation or a set of search terms for understanding:
a. what iPhone 4 does when I hold down the home button to get it out of sleep? it seems to me that this /sometimes/ goes to the Voice Memo function and /sometimes/ it puts a <<  |>|  >> (reverse - play - forward set of buttons) way at the top with my home screen image covering the bottom. I don't understand what this second set does (I tried to use them and they are inactive) and I don't understand if I have options that I can set for coming out of sleep like this.
Also, is there a difference between holding down the home button and just clicking it once or clicking it twice..?
Is there a way to send it straight to record audio like a tape recorder??
I'm searching the iOS5 manual and not coming up with anything.


hi jim.
thank you. also thanks for the link and the page numbers.
can i please ask you a little more here as I try and get up to speed on this?
i do have the phone locked and i think you are right that one click brings me to the unlock screen. two clicks you are saying goes to audio playback which i guess is iTunes? i mean, can i control where this goes? i mean, say i want it to go to an audio /recording/ functionality so that i can record someone speaking. or say i find it uber annoying to go to this audio playback because i /then/ have to click out of it by hitting the home button /again/? i'm not sure (and i can check with your help) but i /think/ that i don't get /anything/ happening sometimes on one click of the home screen and i automatically have thought it is because i should have double clicked it (which i do). anyway, if it only goes to audio playback this seems like a waste of functionality for my uses.
Also, when the phone is /unlocked/ doubleclick goes to a search functionality for me and i'm wondering if there is a way to change this setting - or really /any/ of these type of this-button-goes-somewhere-not-obvious functions...