What is Difference Between Steam and Vapour?

one spelling starts with an 's', while the other starts with a 'v'.

What is this ?

"this" is an undefined pronoun.

One difference is that, for H₂O, when venting into a region at normal room temperature and pressure a jet of steam is invisible, whereas water vapor is visible as a translucent/gray jet of tiny water droplets.

Only superheated steam when vented at a lower pressure (atmospheric) is invisible because it is dry at the lower operating conditions. Saturated steam is an equilibrium state in which both vapor and liquid are present. All answers assumed the steam to be superheated in their comparisons which means you are further away from the phase envelope where only vapor phase exists. The difference between steam and vapour cannot be made because the question neglected to specify the steam state.

there are 3 phase states, solid, liquid and gasous. Then you expand on that with multi-phase states with what I mentioned earlier.

None, a vapour is not an Ideal Gas and hence we use a steam table

Only a colloquial difference, with steam implying higher temperature. Neither is visible, but either can be accompanied by mist/fog/clouds/etc., in which the small liquid droplets are collectively visible.

Steam is H₂O in the vapour phase.

A vapour is anything that is not able to be contained within an open-topped container with the bottom of it pointing towards the centre of the gravitational field

Steam can only be created by heat. Vapour can be created by several means. Think of a atomizer to add moisture to your home. At high enough oscillation the vapor is barely discernible.

for H₂O it's steam above atmospheric pressure and vapour below.

for any other substance it's vapour