OSI Layers and their work

OSI (Open system interconnection) Layers :-

(1) Application Layer :- 

Manipulation of data, mail service etc. are provided, uses web browser.

(2) Presentation Layer :- 

Perform by OS that converts HLL to MLL, maintain encryption & decryption.

(3) Session Layer :-

Manages conversation between two different applications, Manages session b/w source and destination.

(4) Transport Layer :- 

Decides data transmission should be on parallel or single path, It breaks message into packets & maintain it should reach destination with reliability.

(5) Network Layer :- 

Acts as network controller, Decides which route data should take.

(6) Data Link Layer :- Error controlling, Error detection bits are used.

(7) Physical Layer :- Activates, maintain  & deactivate Physical connection, It converts digital bits into electrical signals.

BONUS FACTS :-

Hub :- Works on Physical Layer.

Switch :- Works on Data Link Layer.

Bridge :- Works on Data Link Layer.

Repeater :- Works on Physical Layer.

Router :- Works on Network Layer.

Gateway :- Works on Application Layer.