Apple just released the public preview of iOS 11 for the iPhone and iPad. That means you can test an early version of Apple's next major software release, which will launch this fall. We've been playing with the public preview on an iPad, which Apple says is the "biggest release for iPad ever," for the past couple of days. Let's take a look at the biggest changes coming to the iPad.

A completely redesigned app dock

Todd Haselton | CNBC

You know how you can only keep a few of your favorite apps in the dock at the bottom of your iPad screen? That's completely changing. Apple lets you store up to 13 apps (on my 10.5-inch iPad Pro, in any case), plus 3 more apps, including recommendations from Siri and recently opened apps. This is my favorite new feature in iOS 11.

You can multitask like never before

Todd Haselton | CNBC

Multitasking is being revamped. You can run two apps side by side like in iOS 10, but now also drag out another app, such as Messages, which hovers in its own separate window. This is perfect for when you want to drag a link or an image from one app right into another, and allows you to use your iPad more like a real laptop.

The Apple Pencil is more useful

Todd Haselton | CNBC

If you find yourself taking notes all day long, you'll love this one. The Notes application, for example, knows when the pencil tip touches the screen and automatically makes room for jotting down notes. If you take a screenshot, you'll be able to mark up the page and share it or save it as a PDF. Apple also added a new document scanner, which means signing documents is easier than ever before.

The Control Center can be fully customized

Todd Haselton | CNBC

Control Center, which you might know as that small area on your iPhone where you turn on the flashlight, is entirely revamped. You can now add many more of your own shortcuts, from Home controls to a screen recording function and even Apple TV controls. Tap and hold most of these apps and you'll see even more information (if you tap and hold the music player, for example, you can scrub through the song and view album art).

An easier way to see files and move them around

Todd Haselton | CNBC

The iPad and iPhone finally have an accessible file storage system. You can see various folders you've created on your iPad or iPhone and access cloud-based storage options such as iCloud, Box, Dropbox and Google Drive. iOS 11 even lets you search for a specific file across any service. I love this feature for quickly accessing documents I've been working on on my computer from either my iPhone or my iPad.

Drag and drop is supported across apps

Todd Haselton | CNBC

I mentioned this briefly in the multitasking section, but I'll explain further here. You can now drag and drop content, such as photos, across applications. Maybe you want to send five photos to a family member, for example. Start tapping them inside the Photos app and then drag them right into your email application and send them off. Or, if you have Notes and Safari open, just drag links, images and more right from one app into another.

There's a brand new App Store

Todd Haselton | CNBC