Difference Between OSI and TCP/IP Reference Models

Parameter	OSI Reference Model	TCP/IP Model
Clarification between Services, Interfaces and Protocols	OSI Model clearly distinguishes between Services, Interfaces and Protocols. Each layer performs some services to upper layers, layer interfaces tells the processes above it how to access it, and different protocols are used by different layers as per their needs until a job is not finished.	TCP/IP model does not clearly distinguish between Services, Interfaces and Protocols.
Protocol Biasing	This model is not biased for a particular set of protocols and was developed before corresponding protocols invention.	This Model was developed after inventing corresponding protocols and just was description of existing protocols.
Layers	It is a Seven Layered Model. Which are as follows : a)      Physical Layer b)      Data Link Layer c)       Network Layer d)      Transport Layer e)      Session Layer f)       Presentation Layer g)      Application Layer	It is a 4 Layered Model. Which are as follows: a)      Subnet Layer b)      Internet Layer c)       Transport layer d)      Application Layer
Entity Approaches	OSI uses Horizontal approach in creating application entities. I.e. Strict hierarchy of layers is followed by distributed applications which are constructed from common toolbox of Application Service Elements (ASEs).	TCP/IP uses vertical approach in creating application entities. i.e.  In TCP/IP each application entity contains all the functions that it needs to support a distributed communication system.

OSI Model

Open System Interconnection is a standard that describes how message  is transmitted and received between two points in telecommunication.It is developed by ISO( International Organization for Standardization ). It is a seven layer model and are labeled 1 to 7 with layer 1 at bottom(as per X.200 Recommendations).This concept of a seven-layer model was provided by the work of Charles Bachman, Honeywell Information Services.Idea behind this model was that the telecommunication between two points can be divided into layers with each layer adding its own set of special, related functions. The seven Layers are: 1)Physical Layer 2)Data Link Layer 3)Network Layer 4)Transport Layer 5)Session Layer 6)Presentation Layer 7)Application Layer. these seven layers are divided into two groups. The upper four layers are used whenever a message passes from or to a user(known as Host Layers). The lower three layers (up to the network layer) are used when any message passes through the host computer(known as Media Layers) . Messages intended for this computer pass