Python repeat statement and tuple question. Masters, please help me

I'm taking a course called the return value of a function using a tuple. I'm posting a question because I don't understand something.

names = ["Cheolsoo", "Younghee", "Youngsoo"]

for i in range(len(names)):
    name = names[i]
    print('{} number: {}'.format(i + 1, name))    


for i, name in enumerate(names):
    print('{} number: {}'.format(i + 1, name))    

As you can see, it's a for loop statement. The second code says that you can accept both the order and the value using enumerate, but where did the 'name' (the 9th line) after i+1 come from? I didn't specify a variable like name = names[i] like the first code, but I couldn't understand it even if I turned it around a few times.

The second question.

list = [1, 2, 3, 4, 5]
for i, v in enumerate(list):
    print('{}th value: {}'.format(i, v))


list = [1, 2, 3, 4, 5]
for a in enumerate(list):
    print('{}th value: {}'.format(a[0], a[1]))

Yes, as you can see, they have the same output. I don't know how a[0], a[1] is used here.

Thank you.