The smartphone/tablet world is a mix of complete or partial control by the vendor over what winds up in the end product. When vendors make both the hardware and the operating system, there is more uniformity across models. When they do not, devices may have many different features. This inconsistency can be confusing, while at the same time competition among vendors using the same OS may lead to clever innovations.
Partial Control - Google
Google makes the Android operating system that runs on myriad phones and tablets. Each hardware vendor may make user interface changes and include its own assortment of apps, some of which cannot be removed. See
Android and
Android fragmentation.
Full Control - Apple
Apple is the only organization that has total control over all of the hardware and software, from desktop to mobile. New releases of the iOS operating system are distributed to users' devices with greater uniformity. See
iPhone.
Full Control - Google
Although the hardware is made by other companies, Google exercises a great degree of control over the Nexus and Pixel brands. This ensures a certain look and feel with all models. At one time, Google had total control of the hardware when it acquired the Motorola handset division, but that was later sold to Lenovo. See
Google Nexus and
Pixel phone.
Full and Partial Control - Microsoft
Microsoft owns the Windows operating system, and it sells tablets under the Surface brand, in which case it has complete control of the hardware and software (see
Surface tablet). Numerous tablets are also made by other companies, but the software experience for the user is generally the same.
Microsoft announced end of life for its smartphone business with security fixes until the end of 2019. From 2013 to 2017, it owned the hardware via its Nokia acquisition, although other companies made Windows smartphones as well (see
Windows Phone). See
mobile compatibility and
how to select a mobile device.