How to combine two lists into one?

In Python, two lists can be combined in several ways:

1. Using the + operator:

list1 = [1, 2, 3]
list2 = [4, 5, 6]
combined = list1 + list2
print(combined)  # [1, 2, 3, 4, 5, 6]

2. Using the extend() method, which adds the elements of the second list to the first:

list1 = [1, 2, 3]
list2 = [4, 5, 6]
list1.extend(list2)
print(list1)  # [1, 2, 3, 4, 5, 6]

3. Using list unpacking (Python 3.5+):

list1 = [1, 2, 3]
list2 = [4, 5, 6]
combined = [*list1, *list2]
print(combined)  # [1, 2, 3, 4, 5, 6]

All these methods create a new list or modify the existing one, combining elements from the two lists.