What is the meaning of None in python?

Answer 1

This is used to represent a variable that has no value or type to it.
Even though var = 0 or var = "" may look like a representation of nothing, they still are something.
var = 0 is still an integer (which is zero)
var = "" is still a string (just a blank one)
var = None however has no type. It's not an integer, float, string, or anything (It's officially called a "NoneType").

Answer 2

Robert explained it perfect. But You can do a test in python console:
1) Test for string:
a = " "
if a == None:
print('It is None')
else:
print('It is NOT NONE, I am still string, but empty')

2) Test for int:
b = 0
if b == None:
print('Im None')
else:
print('Im int and I have a value 0!')

3) test with type() function, example:
list = []
str = "abc"
n = 0
nothing = None

print(type(list))
print(type(str))
print(type(n))
print(type(nothing))

Answer 3

None is similar to null which we use in most of the programming languages.