This is probably another dumb question that has already been answered, but I didn't know how to phrase the inquiry using "search." I have a number of iPad apps that are not duplicated on my 3gs iPhone. If I use iCloud, what happens to the syncing process, i.e., will I automatically purchase (or be charged for) the iPad apps that I have––but don't want on my iPhone?

Sent from my iPad using iPF

As long as you use the same Apple ID (iTunes account) on both devices any apps you copy between them will cost nothing.

Only some iPad apps (universal) are compatible with the iPhone. If they are not compatible, you won't be able to download them on the iPhone. Most iPhone apps can be downloaded on the iPad, though if they are not universal they will run in an emulated mode at half size, or pixel doubled.

Apple will never 'automatically' charges you for things. You always have to say OK, and enter your password; though if you make several purchases within 15 minutes you may only be asked the first time. Of course, you also have to do this for apps you've already purchased; so pay attention to where the price usually is. If it says Install or Download, you already own it and will not be charged.

i am wandering what is icloud, i hear that this is a software to avoid your ipad being stolen, even if your ipad is atolen, you can still take measures to find it, is this true?

This should help. Apple - iCloud stores your content and pushes it to your devices.

iCloud is a collection of cloud bases services for iOS devices. Unlike other cloud file sharing services it tends to operate in the background, integrating with apps to keep devices synced, not to give you a general internet place to store and share stuff.

Ok, so how do I get iCloud to sync my iPad and iPhone? Np luck so far.

Apple - iCloud - Learn how to set up iCloud on all your devices.