How does the data plan for the internet access for iPhone 4S work exactly? - 1

I'm going 4S soon (don't care about the 5) and I know that when it comes to when you can access the internet (Safari), you can only access a certain of pages at a time. If I went with the 2 GB data plan then it said somewhere around 100 pages. Does that mean 100 pages per day or 100 pages per month? Also, I was told by a rep.of Verizon that if I'm accessing the Internet using a Wi-Fi connection instead of 3G or 4G or whatever its called, then it won't count towards the data plan at all. Now what if I wanted to access Facebook or Twitter on it? If I used the social networking apps on it instead of Safari, would that count towards my data plan along with using Safari with 3G connection? Please answer my questions because I can't seem to find an answer anywhere.

Added (1). So for the 2GB data plan, I can view more than 100 pages on the internet per day?

1. 2GB is a amount of data you get. It is not counted as websites, facebook post, etc… It is well… Data. Also you can view more then 100 pages/twitter/etc. Then that each day.

2. Go with the 5gb plan. If available to you I think your first phone should be a pre-paid phone (pay first then use).

There's a data calculator on the Verizon website. I can't give you the link since I'm using my phone right now. It's there though, I just used it a couple days ago. It calculates how much data you'll use in a month.
Any time you do anything on your phone that needs to use any kind of Internet, it'll use data, wether it's on Safari or apps (unless you're using Wi-Fi). Just stick to using the apps, unless you're more comfortable using Safari. Be careful with some apps though, some will be running in the background and use data, only a tiny bit though… Not a huge deal unless every bit of data is important to you. So for example, if you're anywhere (like in the car or something) and don't want any updates or Internet service, turn off your data so it won't use any up. Also, don't watch videos using data… God… It uses a BUNCH, REAL FAST! Turn off your data whenever you can. 2GB should be fine though, that's the average for one person. I'm not sure if iPhones have it but on the Samsung Galaxy S3, on the settings, it'll warn me when I reach a certain amount of data (I can set it to any number).