A list is a collection objects that will keep the order, can be changed and can contain duplicates 
my_list = [1, 1, 3, 3, 4, 5]

A dictionary is an unordered collection of key-value pairs. Each key is unique but values can be duplicated. Just like a list, you can add or remove elements 
my_dict = {"a": 1, "b": 2, "c": 2}

A set is an unordered collection of unique elements 
my_set = {1, 2, 3, 4, 4, 5}

Adding an element to the collection 
my_list.append(6)

my_dict["d"] = 3

my_set.add(6)

Removing an element from the collection 
my_list.pop(5) # Remove the nth element from the list

my_dict.pop("a")

my_set.remove(4)

Check if the element is in the collection 
print(3 in my_list)

print("b" in my_dict)

print(2 in my_set)

Joining two collections 
print([1,2,3] + [4,5,6])

print({"a": 1, "b": 2} | {"c": 3, "d": 4})

print({1,2,3} | {4,5,6})

print({1,2,3}.union({4,5,6}))

Comprehensions are a pythonic way to create new collections from an existing one 
print([i * 2 for i in my_list])

print({i: i * 2 for i in my_dict})

print({i * 2 for i in my_set})
Checkout the "for" page to learn more about loops