Network (Graph)

A Network is a collection of connected nodes

What is a Network (Graph) 🎆

A Network is a collection of connected nodes. nodes = elements

Courtesy of NASA taken from ISS

Earth 🌎 🌍 🌏

Viewing earth from the international space station, there is clusters of light in a sea of darkness. These pockets of light are highly connected Networks of people and things people make.

Social Network 🌐

A Social Network is groups of people connected together.

Each line is equal to a friendship

Kyle's Facebook Friend Profile: 🌐

• Family Network:

  • ❤️Wife, Kids, parents, grandparents, cousins, aunts, uncles, inlaws❤️

• Friends Network:

  • childhood friends🍼, work friends👷‍♀️, hobbie friends🏀🎮

• Dank Meme & Programming Network: 💯

  • 😜weirdos🤪more weirdos🤥

I'm personally connected to all these people above in a Network. All of the people im connected to are also connected to their own people. and all of those people are... etc, etc, etc...

I Need a Map, A Map of the Internet! 🧠

Networks are used to represent more complicated relationships and normally used when other data structures simply will not work.

Partial map of the Internet from opte.org

Types of Networks 🌬️ 🌪️

Directed Networks: Connections between nodes flow in a specific direction

• Water always flows in one direction from a higher point to a lower point

  • 🏞️ Water Tower -> Homes -> Sewer 🏞️

• Twitters following/follower system

  • I follow the @PresidentOfTheUnitedStates 🚶

  • The President Of The United States does Not follow me 🚫

Undirected Networks: Connections between nodes flow in both directions

• Facebooks friend system

  • I send a friend request to uncle Jim Bob and he accepts 👯‍♂️

Linked List vs Tree vs Network🍎 🌲 🌎

Linked List and Trees can be represented as simple Networks. The following example explains the differences between the 3 as different types of networks.

Example:

• 7 Nodes = A, B, C, D, E, F, G ✴️ ✴️ ✴️ ✴️ ✴️ ✴️ ✴️ ✴️

Linked Lists: a simple directed network where each node flows to the next node. 👉

• (start) A -> B -> C -> D -> E -> F -> G -> END

Trees: are a directed network where the starting node flows down to multiple nodes 👈👉

•            (start)
                A 
                '
        -------------------
       '                   '
       B                   C
       '                   '
   -----------         -----------
  '           '       '           '
  D           E       F           G

Networks: can be used to diagram highly connected systems👈👉👆👇🤙

• - = 2-way connection
  ' = 2-way connection
  x = 4-way connection
  No starting point 
  No ending point

• A  -  B  -  C
  '  x  '  x  '
  D  -  E  -  F
  '  x  '  x  '
  ----- G -----

The key takeaway is all systems have the same number of Nodes but a different number of Connections. The Connections are what make the data structure a linked list, tree or network.