One of the biggest alterations will be the introduction of Material Design - a new design language that puts more of an emphasis on shadows and colors. There are a handful of under-the-hood improvements, too, such as Project Volta, which is a collection of back end enhancements meant to improve battery life.
But, unlike the iPhone, Android devices don't get major software updates all at the same time. It depends on which type of phone you have and which carrier you're on.
There are also tons of Android phones that are left out of major carrier updates too.
We still don't know exactly when Android 5.0 will be released for every phone, but here's a roundup of what we know so far.
Google's Nexus 6 will come with Android 5.0 already installed, and both the Nexus 4 and Nexus 5 will receive the update too. Google hasn't announced when it will launch, but Google has reportedly given developers a date of Nov. 3, according to blog Android Police.
HTC
HTC's One M8 and previous-generation One M7 will both get Android 5.0 as well. Jeff Gordon, the company's global online communications manager, tweeted that both phones will get the upgrade within 90 days of the software's final release.
Motorola
Motorola announced last week that its first and second generation Moto X and Moto G will get Android 5.0, along with the Moto G LTE, Moto E, and Droid Ultra, Droid Maxx, and Droid Mini phones.
Samsung
Samsung hasn't made any official announcements regarding updates for its line of smartphones, but rumors suggest the Galaxy S5 will be able to upgrade come December. Samsung also teased an Android Lollipop update for its new Galaxy Note 4 via Twitter. It's likely that Samsung's other popular phones, such as the Galaxy S4 and Galaxy Note 3, will also get the upgrade, but we haven't heard anything just yet.
LG
LG hasn't revealed which of its phones will get Android Lollipop yet either. However, rumors from tech blogs such as GSM Arena and PhoneArena suggest the LG G3 will get the update before the end of the year, and the G2 will receieve the upgrade in early 2015.
We'll update this story as more carriers and manufacturers make announcements.