What are % and %s?

[snippsat]

for quiz_num in range(2):
    print("The old way,don't use it' <%s>" % quiz_num)

for quiz_num in range(2):
    print('A newer way format(),ten year old comes out with 2.6 <{}>'.format(quiz_num))

for quiz_num in range(2):
    print(f'The new way f-string 3.6 <{quiz_num}>')

Output:
The old way,don't use it' <0>
The old way,don't use it' <1>
A newer way format(),ten year old comes out with 2.6 <0>
A newer way format(),ten year old comes out with 2.6 <1>
The new way f-string 3.6 <0>
The new way f-string 3.6 <1>