How does a speech differ from an essay?

There's a huge difference between speeches & essays.

For example, reading an essay aloud to an audience can and will bore them to tears.The key difference huge between the two is that one is crafting a speech that is meant to be read aloud and it's purpose is to engage the listener. An essay, however, is written using straightforward facts and it contains no usage of the words "I", "We", "Us", "Myself" or anything that relates people. 

With an essay you're stating facts or maybe stating facts and giving your opinion. wiht speech youre trying to  convince your audience tht what youre saying is correct and that they should go along with what youre saying.