Diffrence between EDI and IDOC

EDI stands for Electronic data Interchange.

SAP will support EDI through Intermediate documents (IDOCS).

EDI (Electronic Document interchange) - EDI is the electronic exchange of business documents between the computer systems of business partners, using a standard format over a communication network. 

EDI is also called paperless exchange. 

Advantages: 
Reduced Data entry errors
Reduced processing time
Availability of data in electronic form
Reduced paperwork
Reduced Cost
Reduced inventories and better planning
Standard means of communications
Better business process

EDI has two process
Outbound process
Inbound process

OP:
1.Application document is created.
2.IDOC is generated
3.IDoc is transferred from SAP to Operating system layer
4.Idoc is converted into EDI standards
5.Edi document is transmitted to the business partner
6.The Edi Subsystem reports status to SAP

IP:
1.EDI transmission received
2.EDI document is converted into an IDOC
3.IDOC is transferred to the SAP layer
4.The application document is created
5.The application document can be viewed.
 

IDOC:
IDOC is a container that can be used to exchange data between any two processes.
Each IDoc is assigned a unique number for tracking and future reference.
IDoc Consist of several segments, and segments contain several fields.
IDoc contains the following three type of records...
1. One Control Record.
2. One or many Data Record
3. One or many Status record.

PORT:
Port is used in the outbound process to determine the name of the EDI subsystem program, the directory path where the Idoc file will be created at the operating system level, the Idoc file names and the rfc destinations.

RFC Destination:
Used to define the characteristics of communication links to a remote system on which a functions needs to be executed.