There are two popular mobile operating systems available for smartphones which are iOS from Apple inc. and Android from Google while iOS is closed source thus no one else can use it and then Android is FOSS - free and open source so anyone can build thier own version of Android OS with optimizations like removing or adding features due to that in short time Android OS is well utilised by companies and developers on smartphones.

Fortunately, in just few years Android OS worldwide market share increased to more then 75% thanks to mobile companies and developers who always loaded Android OS on almost all smartphones but majority of Android OS smartphones are outdated as mobile companies usually stop upgrades and updates to Android OS smartphones after 1 or 2 years for various reasons.

The primary reason why most mobile companies don't provide Android OS upgrades is because it's not easy they have make an Android OS update based on hardware specifications of smartphone that is bit hard and takes time even if they manage to build Android OS in less time then very likely it was not fully optimized due to that you may likely find bugs which is why many mobile companies take years to give Android OS upgrades and updates.

While, some mobile companies intentionally stop Android OS upgrades and updates on thier old smartphones for business and marketing reasons like to make people and existing customers to buy thier new smartphones for latest Android OS versions which is working for them but at the same time alot of Android OS users who want regular updates and upgrades shifting to Apple inc. iPhones.

iPhone 1 is world's first revolutionary multi-touch technology smartphone made by Apple inc. that boasts an advanced closed source operating system which don't have name in first release but later on Apple inc. from iPhone 2 named it's operating system as iOS and started providing numerous software upgrades and updates timely to even old iPhones.

In sense, Apple inc. provide software upgrades and updates to iPhone more years then Android OS so you'll get pro-longed security and privacy on iOS but iPhone is expensive thus not everyone can afford especially people from developing countries so they instead like to buy less expensive Android OS smartphones.

Anyhow, Majority of Android OS market share is largely consists from developing countries and most people using outdated Android OS smartphones as they don't like to switch smartphones often so it is very important and responsibility of Google to provide an facility for mobile companies and developers to make and release latest Android OS upgrades quickly.

Google, in order to fix late and in-consistent Android OS upgrades and updates from mobile companies launched Android One program in which any mobile company can join to partner with Google to make and release stock Android OS upgrades and updates timely for atleast minimum 2 years but that didn't worked out well as most mobile companies didn't shown interest to join Android One except few like Xiaomi and Nokia.

Android One program didn't got much success because most mobile companies make and release custom Android OS version on thier smartphones to name few like Xiaomi's, MIUI, Samsung's One UI and Meizu's FlymeOS etc so they didn't show interest and focused on Android One as thier customers like to use custom Android OS.

However, even custom Android OS are build on top of stock Android and big percentage of people use custom Android OS but lacks regular software upgrades and updates so to fix this problem Google made and released Project Treble by using that mobile companies or developers can simply upgrade smartphones to latest Android version in less time.

Treble project is released in year 2017 and officially enabled on Android 8.0 Oreo version smartphones and pre-supported by most smartphones which re-structured Android OS to provide quick software upgrades and updates even on old smartphones as with Treble support mobile companies and developers don't have to build Android OS from scratch instead they can use GSI.

GSI aka Generic system image is released by Google which will work as base that anyone build and use on smartphones even GSI of other smartphones can be used on complete new smartphone with little modifications as on GSI you don't have change vendor of smartphone that was required prior Project Treble.

In sense, on Project Treble you'll get reworked and stable vendor that has access to hardware specific parts of Android OS thus mobile companies can simply can use Android OS framework to easily push smartphones to new Android OS versions isn't big step from Google?

Unfortunately, majority of Android OS smartphones still don't support Project Treble as they probably using old Android OS versions like Android 7.0 even though mobile companies can add project Treble support by upgrading to Android 8.0 Oreo yet they didn't do because it will for sure drop sells of new smartphones.

But, thankfully third party developers using various methods enabled Project Treble on old unsupported smartphones even build number of GSIs and revived numerous old smartphones to new Android OS versions due to that Project Treble is in continuous usage even though mobile companies are very much not relying on it.

Anyhow, it is not easy to build GSI for smartphones it's lengthy process but a developer named phhusson created many scripts to simplify development of GSI by using them you can easily make GSI but still do remember you must have powerful PC or cloud server with knowledge on Android OS development else you may probably hard or soft brick your device.

Now we have latest Android OS GSI for many smartphones even to those which are 5 to 6 years thanks to alot of developers who contributed to buid GSIs for number of devices like for instance Erfanoabdi who created tool to build GSIs easily but in order to install GSI you have to unlock bootloader then install custom recovery like TWRP aka TeamWin recovery project using guides from trusted portals like XDA that voids device warranty.

Eventually, Custom rom developers who used to build and port stock GSIs also started building GSI for thier custom roms then porting them to other smartphones due to that now we have have thousands of GSIs for people to use but do note not every GSI is compatible with your device so you may find bugs as it depend on your device vendor and kernel etc.

Remember, if you're amazed by Project Treble and want to install GSI on your smartphone then it is recommended kindly make sure to backup your current custom rom or GSI with vendor thus if you ever face any bugs or issues on new GSI then you can simply restore back to existing supported custom rom or GSI that saves time and keep you in safe zone.

Atlast, Treble is solid project from Google to fix mobile companies late upgrades and updates of Android OS that will work for long time but I doubt will Treble Project will be continued in future if Google plans to bring it's new operating system Fuchsia OS on smartphones that has zircon kernel which is designed to provide fast software upgrades and updates then Android OS.

Finally, this is Google's Project Treble by using that we can generate GSI which allows you to provide quick Android OS upgrades and updates, are you an existing user of Project Treble GSIs? If yes do say your experience and mention which GSI you use on your smartphone in our comment section below, see ya :)