OSI  has  seven  layers and TCP/Ip has only  4 layers

osi -7layers tcp 4-layers

osi is a 7 layer model & it's difficult
tcp is a 4 layer model & it's much easy than osi model & 
tcp model is fast dovleped than the osi model 

OSI is a standard "reference model" that describes how 
protocols should interact with one another. Invented by the 
Department of Defense, TCP/IP became one of the "standards" 
that enabled the Internet to become what it is today. 
TCP/IP doesn't map cleanly into the OSI model.

OSI  has  seven  layers and TCP/Ip has  4 layers.

osi has both the session layer and the presentation layer
whatever tcp/ip combines both into an application layer.

tcp/ip has 5 layes somewere somewere it is 4 layers and in
osi it has 7 layers tcp is the better model of understanding
internet protocols and transmission of data 
it is much better then osi model 

1.Both connectionless and connection-oriented communication
are supported in the network layer, but only
connection-oriented communication in the transport layer.  
      2.Seven layers, Network (Internet), Transport and
Application layers being similar to TCP/IP
3.Only four layers
4.Because models were invented before protocols,
functionalities put in each layer are not very optimized
5.In this case, the protocols have been invented before
models, so the functionalities are perfectly described
6.Service, interface and protocol are not clearly defined.
For example, the only real services offered by the Internet
layer are 
- Send IP Packet 
- Receive IP Packe
7.Protocols in the OSI model are better hidden and can be
replaced relatively easily as the technology changes, which
is one of the main objective of layered protocols