Hello i want to buy Motorola One but i hear it will be supported only for three years i want to know after three years i will receive updates or the software will end?
It'll still work after the three years but software updates may well cease, three years is quite a long time in mobile phones and a lot can change, many people have and use phones that are a lot older and they still work without updates, although you could argue that security wise they may not be as safe.
With most phones, you get software updates for only two years from date of release (not from date f purchase). The phone will still work (my 2013 Note 3 still works), but you miss out on security patches and new versions of Android.