As the release date of Android 6.0 M, (now known to be Android 6.0 Marshmallow) approaches, users of Google's mobile operating systems may be wondering what's coming in the update that's different from the last operating system it released, Android 5.0 Lollipop.

Lollipop brought major changes to Android, bringing the operating system into the new era with more control over notifications, smarter anti-theft mechanisms built-in, and a completely new look to the system based on "Material Design." To see everything Lollipop brought when it hit Android devices everywhere, check out our hands-on review.

So what's so big about Android 6.0 Marshmallow, and what could Google bring to the operating system that warrants an entire new name, and not an incremental "5.2 Lollipop" designation? Here are the biggest changes coming this fall when Android 6.0 M for Marshmallow hits the consumer market.

Same Battery, More Life with Doze

Perhaps the biggest, most anticipated feature of Android 6.0 Marshmallow will be the most boring-sounding one: Doze.

Don't be deceived by the name, Doze could be a big wakeup call to your Android's battery. Google has released some information on Doze, most notably during its developers conference earlier this year, but full details are still being kept mum for now.

Doze is a feature that is expected to save some major hours of battery life by intelligently putting parts of your Android system into idle mode when you haven't touched it in a while.

Doze knows if it's idle based on your smartphone or tablet's various motion and position sensors. If you don't seem to be using your Android device, Doze will kick in and put background apps into an idle state and pause other processes that bit by bit, slowly drain the battery of your smartphone. Alarms and important notifications will still remain active, even in this deep sleep mode.

When you pick your phone back up, Doze is designed to instantly kick everything back into gear, getting those paused sync processes back up and running. When all is said and done, Doze is being touted as a way to possibly double the average battery life (depending on how often you use your phone throughout the day, of course).

That's big, and it's probably worth smaller, less important app notifications and syncing taking a load off when you're not using the phone.

Google Now 'On Tap'

Google is bringing enhanced Google Now features to the small screen with Google "Now on Tap," which it also announced during Google's I/O conference this year.

Now on Tap is basically being touted as a way to make your smartphone even smarter, by vacuuming up as much contextual information about you as it can. This includes information in third-party apps, your email, the articles you read, the music you are listening to, and where you are or where you are headed.

The enhanced Google Now will try to combine all of those elements that it can and then offer you information and suggestions before you're aware you need it.

For example, if you have an appointment scheduled, it will of course remind you, but it may also provide information on where you parked as you head out to your car, plus a Spotify playlist you just started listening to for driving music. Yes, it's all a little creepy, but creepy convenience may be something to get used to.

More Power Over App Permissions

Perhaps mitigating the creepy factor, Google is finally introducing something that it should have a while ago (like Apple did): a simple way to approve or deny apps certain permissions to access your phone or information, on a case-by-case basis.

Until Android M, when you'd download an app, you would get a laundry list of permissions that you could either allow (if you wanted the app), or decide to not get that app. Guess what you're more likely to do in the moment, right?

Now, Google has simplified the permissions into just eight categories, and by default those permissions will only be asked for when you need them. So if you want Facebook Messenger to access your contacts, but aren't comfortable with it having access to your microphone or location data, with Android M you'll have a say in that.

Faster Charging with Next-Gen USB Support

Whether or not Google reveals new Nexus 6 and Nexus 5 devices with the connector of the future, USB-C, Android 6.0 Marshmallow will come with software support for it.

This may be something that's only useful to you down the line if you already have a relatively new Android device (with microUSB) that you're currently happy with. But just imagine the future: a charging cord that can be plugged in either way, ending the three step plug-flip-plug dance forever!

More Android 6.0 Marshmallow features may be debuted at the upcoming Google event next week, so stay tuned for more updates.