You need ' or " to make a string. What you use is a matter of style or convention both will work, just use them consistenly. ("this' is no good)
I think mostly " are used for strings that represent sentences in human language like
"hello world"
and ' are used for more abstract strings like single charaters etc.
You can use single or double inverted comma's to create string .but if you want to do tricks with your String then you can try both.
e.g=
x=('"Hi"')
print(x) output="Hi" because "" is also a string here.
