what is the difference between on and onto

Dear student,

The main difference between the two words is that onto is about movement from one place to another while on is not. For example -

I walked onto the bridge and took a photo. This means that I was not on the bridge at first. I walked there from some other place.

I walked on the bridge and took a photo. This means that I was already on the bridge and was walking around on it.

Hope this information will clear your doubts about topic.
If you have any more doubts just ask here on the forum and our experts will try to help you out as soon as possible.
Regards