I am today going to clear you about OIS and EIS, let me tell you in start only, that OIS is hardware based solution and EIS is a software-based solution, let's start with optical image stabilization, as I have mentioned this a hardware solution and generally we find OIS in high-end smartphones like of apple devices because its a lot more expensive to establish OIS, actually for OIS, the lense are floating, so when we click pic with moving hand, due to its floating tech, it manages to stabilise the image, but as I said it is very expensive to establish,so not found in budget smart phones.
Types of OIS
2 axis OIS
3 axis OIS
5 axis OIS
In short, OIS helps by physically moving the lens, that is all about OIS, and you can not add optical image stabilization with the software update as it is a hardware-based solution.
Now let's talk about electronic image stabilization,
This started becoming popular from last year even in smartphone and as we know it's a software-based solution so don't require any kind of special hardware, this is done of either sensor or sometimes it is done after you shoot pic or video, so processing power is actually required for EIS,technically speaking many EIS solution are also using gyroscope sensor ,for example with gyroscope they can detect how you are moving your phone while shooting, so that info also captured and compensated by sensors, so by this we get stable pics even without any hardware.So in short if a smartphone has the good processing power, then they can implement EIS with a software update.
An example : One plus 5 : When it was launched, the shooting of 4k used to be very jerky and movements were not good because when it was launched they didn't implement any EIS, but as One plus 5 had gyroscope sensor and pretty powerful chips so two months later they implemented The EIS with software update.
Later in 2017, there are some smartphones like Google pixel 2 that applied hybrid image stabilization, that means they applied both OIS and EIS.
But in my opinion, OIS is best for clicking pic and EIS is best for shooting videos, so I hope you guys now have clear understanding of OIS and EIS