KaiOS is practically a single program, Firefox (37 on KaiOS 1.0 and 48 until KaiOS 2.5.2). The structure of KaiOS is the same as Firefox OS, whose lightness is based only on three levels:
Gonk, which is the lowest level and which mainly contains the linux kernel;
Gecko, which manages boot processes (b2g) and system-level permissions (such as installing applications), is sufficiently powerful and autonomous to be able to manage perfectly and safely all the authorizations necessary to make the operating system work;
Gaia, the user interface, is mainly made up of web contents (webapps), written essentially in HTML, JavaScript and CSS.
Having said that we can assume that the applications we are using are nothing more than the tabs of the navigation of a normal browser. This also makes us understand that any website can become a webapp. So being able to move a website offline on your device makes it a full-fledged webapp. That's why the structure requires at least 256 MB of RAM.
