(Question)
I would like to identify
(Answer)
Thank you for contacting the Toronto Master Gardeners.
Your photo shows a beautiful example of a Deutzia gracilis. This shrub grows best in average, medium moisture well-drained soil in either full sun or part shade.
I have attached a link below which will give you more information on this lovely flowering addition to any garden.
Deutzia gracilis | Landscape Plants | Oregon State University
Hope this is helpful.