Canvas:-Canvas means a strong coarse kind of cloth used for tents and as a surface for oil painting.
Canvass:-To convince or solicit.(Solicit votes)
Students went for canvassing before the school elections.
Canvas:The shoes are made of canvas.
The students wear canvas shoes to school.
When sunita went to meet her friend he was painting on the canvas.
Canvass:The workers have been canvassing for votes.
The polititians were canvassing for votes in their locality.