When I do something like this:

x="hi echo hello" 

or

x='hi echo hello' 

Then x will contain the string hi echo hello.

But when I don't use quotes:

x=hi echo hello 

Then x will contain the string hi, and the command echo hello will be executed.

But what about when a variable's value only consists of a single word, is there a difference between the following:

x="hi" x='hi' x=hi