🛜 7 Layers of the OSI Model vs TCP/IP Model Visual Guide:
The OSI model (Open Systems Interconnection) is a seven-layer theoretical stack that can be used to explain how a network works.
The concept was established to standardize networks in a way that permitted multi-vendor systems; before this, you could only have a single-vendor network because the devices could not communicate with one other.
𝗢𝗦𝗜 𝗠𝗼𝗱𝗲𝗹 𝗟𝗮𝘆𝗲𝗿𝘀
As I have mentioned above, the OSI model consists of 7 layers. These layers work together to make the network work properly.
💻 𝗔𝗽𝗽𝗹𝗶𝗰𝗮𝘁𝗶𝗼𝗻 (𝗹𝗮𝘆𝗲𝗿 𝟳)
This is the layer closest to the end user. This is the layer through which the application and the user communicate.
For communication between web browsers and web servers, application-specific protocols such as HTTP (Hyper Text Transfer Protocol) are utilized at this layer.
📝 𝗣𝗿𝗲𝘀𝗲𝗻𝘁𝗮𝘁𝗶𝗼𝗻 (𝗹𝗮𝘆𝗲𝗿 𝟲)
This layer formats the data so that it may be understood by the receiving application. This layer can also encrypt data as it is sent and decrypt it as it is received, ensuring that only the intended recipient can read it.
🍪 𝗦𝗲𝘀𝘀𝗶𝗼𝗻 (𝗹𝗮𝘆𝗲𝗿 𝟱)
This layer controls host-to-host communication (sessions). It creates, manages, and destroys connections between a local application (such as your web browser) and a remote application (for example, YouTube).
🚗 𝗧𝗿𝗮𝗻𝘀𝗽𝗼𝗿𝘁 (𝗹𝗮𝘆𝗲𝗿 𝟰)
To ensure that no data is lost, the transport layer is employed for error handling and sequencing. This layer also provides host-to-host communication also know as end-to-end communication.
🌐 𝗡𝗲𝘁𝘄𝗼𝗿𝗸 (𝗹𝗮𝘆𝗲𝗿 𝟯)
The Network layer connects end hosts on different networks (i.e outside of your LAN). This layer handles logical addressing using IP addresses.
🔗 𝗗𝗮𝘁𝗮 𝗟𝗶𝗻𝗸 (𝗹𝗮𝘆𝗲𝗿 𝟮)
This layer facilitates node-to-node communication and data transfer (for example, PC to switch, switch to router, and router to router).
The physical address (MAC Address) is appended to the data at this layer, this includes the source and destination MAC addresses.
🔌 𝗣𝗵𝘆𝘀𝗶𝗰𝗮𝗹 (𝗹𝗮𝘆𝗲𝗿 𝟭)
The physical layer is the OSI model's bottom layer. It specifies the physical properties of a medium that is used to carry data between devices. For example, Voltage levels, maximum transmission distances, physical connectors, and so forth.
Digital bits are transformed into electrical signals for wired connections and radio signals for wireless transmission at this layer.
