Origin of computer

In the past, computers were big and worked really hard in isolation. Computers were bigger at the past, but they became smaller and smaller. examples: Arpanet(the first net). The computer devices like sensors and lap with the green font came up.

Hard for working alone

Computers are hard to work with alone. They want to be able to change data without actually having to constantly use secondary memory. Computers want to talk each other.

How computers talk?

Actually, they don’t talk each other. Computers understand electricity and electrons. The electrons represent the number system. People started forming the computer system with the purpose. Therefore, they got computer and need the computer network.

definition of computer system and network

  • Computer system: a group of computing devices and programs working together for a joint purpose.
  • Computer network: a group of interconnected devices of capable of sending or receiving data

Path

Sometimes, it is pretty inundated. However, it is called bandwidth. It is important to know how long the message will send. The packets send through this path.

Reason of having connection

It is important to connect with others. It can make easier to communicate. It can also transmit data to make things a little bit easier.

vocabulary

Path is a sequence of directly connected computing devices that begins at the sender and ends at the receiver Computer system is a group of computing devices and programs working together for a common purpose Computer device is a physical artifact that can run a program. Some examples include computers, tablets, servers, routers, and smart sensors Bandwidth is the maximum amount of data that can be sent in a fixed amount of time Route is the process of finding a path from sender to receiver Computer network is a group of interconnected computing devices capable of sending or receiving data

Packet and Protocol

Packet is a small amount of data sent over internet. The information of destination and message are include on it. The protocols are the rules in the path. If packet is a car and drives in the path, they have rules to behave. The mother of Protocol is OSI model.

Four layers

  1. Network access, this layer deals a lot with the hardware case, setting up things in the hardware in order to go ahead and send things along. This usually start with internet cable or a network internet card(= Mac address)
  2. Internet, this layer have sender Ip and receiver Ip. This is where packets get set up with metadata. They are interchanging their information in this layer, and it’s flowing right through, and meeting its destination. This layer is essential that people get their Ip address.
  3. Transport, autonomous systems are controlled by internet provider. There the thousands of autonomous systems try to join bigger version of internet. This happens in this layer. TCP and UDP is a popular examples of it. TCP is a lot, it’s stricter, in the sense that it makes sure that the package has been delivered, and it does this by what we call a three hand way handshake like certified mail. UDP is more lax. It’s like best efforts, like putting the envelope, package in the mailbox, and saying about getting these.
    • IP is given to us, and using 32 bits and four octets. Bits is a true way to communicate in computer.
  4. Application layer, domain name service is in this layer. Domain name service is actually database that maps all these lovely little Ip numbers to name, names that we understand. World wide web is not an internet. It’s a bunch of linked data pages. HTTP is protocol used by World wide web.