What is the Difference Between Set and Sequence

        What is the Difference Between Set and Sequence .

Sets:

The symbols ∈ and ∉denote set membership and non membership, respectively.
example: 9 ∈ {9,11,37}and 2∉ {9,11,37}
Subset: A ⊆ B , Every element of A is an element of B.
Proper Subset: If A is a subset of B and not equal to B.
Multi set: {7} and {7,7} are different as multi sets but identical as sets.

Infinite set: natural numbers N    ={1,2,3,m}  and integers Z={

m ,-2,-1,0,1,2,},

contains infinitely many elements.
Empty set: Set with 0 members, written as Ø.
{n rule about n}: A set containing elements according to some rule.
={n n =    m2 for some m ∈ N}means the set of perfect squares.

Cardinality of a set: the number of elements in it. Set Operations:
Compliment: A , is the set of all elements under consideration that are not in A.

Sequence :

 

Sequence: a list of object in some order
(9,11,37) is a sequence of 9, 11, and 37
Order matters, so (9,11,37) is not the same as (11,9,37).

Repetition is allowed, so (9,11,37) is not the same as (9,11,9,37).
Tuple: Finite sequence.
K-Tuple: A sequence with
Pair: A 2-tuple is called a k elements.