Unpacking assigns each item of a tuple (or list, or any sequence) to its own variable, in one line:

point = (3, 7)
x, y = point
print("x is", x, "and y is", y)

name, age, city = ("Ada", 36, "London")
print(f"{name} ({age}) lives in {city}")

The number of names on the left has to match the number of items, or Python raises a ValueError. This is what was happening with name, age, city = line.split(",") in the last unit.

Unpacking gives Python its famous one-line swap. The right side is packed into a tuple first, then unpacked into the names on the left:

a = 1
b = 2
a, b = b, a
print(a, b)