A "hypothesis" is just an idea or proposal which someone comes up with
to try and explain a given set of observations. A hypothesis must be:
a)
falsifiable/disprovable
b) testable
c) have predictive value, in
order to be taken seriously by scientists, and to begin its journey
towards the status of "theory".
If it is an interesting proposal and is
deemed to possess these 3 criterion, scientists will start to
investigate it: what can it predict, what does it explain, is it
compatible with all the relevant data/observations? If it is supported
by enough experiments and/or observations, and gains acceptance by
enough of the "scientific establishment" (ie, by enough scientists who
are accepted and admired by their peers), at some undefinable point it
becomes a "theory". It can still be disproven at any time, but until
that happens it will remain a "theory" and may even graduate to the
status of "well supported theory", such as the theory of gravity or
relativity. At NO point, however, is ANY theory ever considered by
scientists to have been "proven": in the scientific world, all truth is
"relative". and provisional.
