There are some clear distinctions between commands and events but there are also some not so clear. I discuss the notion of a command as an interpretation of an event.
Commands are requests to do something, they are named in the imperative tense and capture intent. In CQRS, commands are distinguished from queries because they invoke behaviors therefore causing state changes whereas queries don't. In some frameworks, there is a distinction between commands and events in that one sends commands and publishes events. Commands are sent to a single logical handler whereas events are broadcast to potentially multiple handlers.
Events are characterized as being in the past tense. In addition to naming this imposes the constraint that events can't be rejected - you can't change the past. Furthermore, an event can be regarded as an outcome of a command - a causality relation.
There are perspectives where the distinction blurs. For example, what is the distinction between a command handler and an event handler?