Android Kitkat brought many storage problems and headache to the App developers, users complained about this many times and the only solution is to Root your phone to be able to transfer files from the Internal storage to the external storage (microSD cards). Google finally solved this problem with Lollipop.
Now with the release of the final version of Android 5.0 Lollipop, new APIs were added to allow apps to request full access to directories owned by other providers. These APIs have been improved to offer more capabilities than before, and they do it in a very user-friendly and secure way. You'll no longer have to Root your phone to access/modify your microSD data.
Here's what Google Developers said about lollipop shared storage devices:
Richer access to secondary shared storage devices
In KitKat we introduced APIs that let apps read/write file in app-specific directories on secondary storage devices, such as SD cards.
We heard loud and clear that developers wanted richer access beyond these directories, so in Lollipop we added the new ACTION_OPEN_DOCUMENT_TREE intent.
Apps can launch this intent to pick and return a directory from any supported DocumentProvider, including any of the shared storage supported by the device.
Apps can then create, update, and delete files and directories anywhere under the picked tree without any additional user interaction. Just like the other document intents, apps can persist this access across reboots.
This gives apps broad, powerful access to manage files while still involving the user in the initial selection process.
Users may choose to give your app access to a narrow directory like "My Vacation Photos," or they could pick the top-level of an entire SD card; the choice is theirs.
The S6 was launched in 2015 and it was considered by many to be the smartphone of that year. Even after that, it was far from being perfect as the S6 suffered from a number of noticeable flaws. One of those flaws was forceful memory management which made multitasking on the S6 not as good as it should be with a device that's sporting 3GB of RAM and top of the line hardware. At first it was thought to be an embedded flaw of Android 5.0 Lollipop itself, but it was soon proved to be a "feature" found in TouchWiz. This feature was originally designed to provide users with the smoothest experience possible, but it killed background operations faster than it should and even when not needed.
The Galaxy S7 however, is handling multitasking much better than its predecessor. As seen in a YouTube video by Erica, it can juggle between at least eight applications that are running simultaneously in the background. Things got a little tense when Hearthstone Heroes of Warcraft was launched. By tense, we mean that after opening the game, Chrome browser had to reload the last visited page even though it was already open and running in the background. This is actually a good thing in our opinion as this will only ensure that the user's gaming experience is always smooth. It looks like the RAM management system is finally working better compared to last year, although there might still be room for improvement over time through patches and updates.