On is a versatile word with multiple meanings. In its most basic form, it can be used as an adverb to indicate the presence or occurrence in a particular place or state. For example, “He was on the bus” means he was present then. It can also mean being in physical contact with something: “The cat is on my lap,” which implies that the cat and I are touching each other at that moment.
On has many other uses as well; for instance, when talking about motion towards something, it indicates movement from one point to another: “She walked on down the street,” which means she continued walking further along said street until reaching her destination (or stopping). Additionally, when referring to someone’s behavior or attitude towards others, it signifies their readiness and willingness to do so; for example, saying “he’s always been very much ‘on’ whenever we’ve needed him” expresses his dependability and eagerness in helping out his friends whenever they require the assistance of any kind.
Regarding technology usage, On often refers to either directly or indirectly related activities such as turning things “on” (i.e., powering them up) or connecting/activating specific applications such as Wi-Fi networks, etc. It may also refer, more generally speaking, to being online and connected via the internet – this could include browsing websites, checking emails, etc.
Finally, On can be used metaphorically, too, indicating readiness/preparedness e..g, saying someone is “on top of their game” implies they are doing well / performing excellently.