It wasn't until I tried loaning a device to a friend learning about ebooks that I really thought about the difference between a Kindle ereader and an iPad. A reader is like a book, accept for a few things. A very lightweight reader can contain hundreds of books and books can be added or subtracted as much as desired. What can feel amazing is that a book can be found in the Kindle store using the Kindle and downloaded in less than a minute with either device. We don't pay for a special cellphone signal so we need to be connected to Wi-Fi at home or elsewhere. When connected, the file that makes the ebook gets sent to the default device of choice.
I have a Kindle Paperwhite and an iPad Mini. Neither has unlimited memory and can get full. So, I made my default reader the Kindle Cloud reader, which is the set of files on Amazon computers of books i have in my Kindle archives. I don't usually read in a browser but I could do so on any computer that has an active internet connection.
The iPad is an attempt to make a computer as powerful and handy as a desktop or laptop computer in a device of the size and feel of a clipboard. Since the iPad launch, the term "tablet" has become common usage for an iPad or competing tablet. The iPad is basically run using various "apps" or applications (a.k.a. software program-ettes). Apps are downloaded from the app store using the iPad itself. Some apps cost $1-3 and some more than that, but many are free.
The main thing is that a Kindle is for reading and it is very good for that purpose. The iPad can have a free Kindle app loaded onto it and can then act very much like a Kindle reader. Both can change the font to different sizes and types. The Kindle has a dull backlighting while the iPad emits a stronger light but it can be adjusted for intensity. I had enough eyestrain after a day of computing and an hour of reading with the iPad that I began using artificial tears but after switching to the Kindle Paperwhite, I have no eyestrain. But the iPad can do many other things besides let the user read a book from Amazon (or Barnes and Noble, as a Nook). It can quickly check the weather, play games with friends located somewhere else, access Google search engine and other Google services such as Voice, which I use for texting. There are thousands of apps and some of them are very good and very popular.
I guess that if you try to read books on an iPad, you are going to be distracted by all the other things it can do. If you want to explore new areas, great. If you want to concentrate on getting more reading done, try the Kindle Paperwhite.
--