Definition of various car segments?

As per SIAM (Society of Indian Automobile Manufacturers)

The classification of segments are done as per length of the vehicle, (Passenger car segment)

A1 - Mini - Upto 3400mm (M800, Nano)

A2 - Compact - 3401 to 4000mm (Alto, wagon r, Zen,i10,A-star,Swift,i20,palio,indica etc)

A3 - Midsize - 4001 to 4500mm (City,Sx4,Dzire,Logan,Accent,Fiesta,Verna etc)

A4 - Executive - 4501 to 4700mm (Corolla,civic,C class,Optra,Octavia, etc)

A5 - Premiun - 4701 to 5000mm (Camry,E class,Accord,Sonata,Laura,Superb,etc)

A6 - Luxury - Above 5000mm (S class,5 series etc)

B1 - Van - Omni, Versa, Magic etc

B2 - MUV/MPV - Innova, Tavera, Sumo etc

SUV - CRV, Vitara etc

A segment, B segment etc were used earlier, tho new terms came, still old one is used most popularly.

But now the segmentation in india is done on the basis of length

That was the segmentation of car. Now there is one more thing, classification by shape.

ONE BOX (VAN/MPV) - It means Engine area, Passenger area & luggage area all in one box. There wont be separate compartment. For eg. Omni, Ace Magic, Versa

TWO BOX (HATCHBACK) - It means Engine are has a separate cabin while Passenger area and luggage area are together. For eg. M800, Alto, Santro, i10, A*, Swift etc.

THREE BOX (SEDAN/SALOON/NOTCHBACK) - It means Engine area, Passenger area & luggage area all are having different cabin. For eg. SX4, City, Fiesta, Dzire, Ambassador, Indigo CS etc.

ESTATE/STATION WAGON - Its nothing but sedan whose roof is extended till the rearto create more boot space. For eg. Indigo Marina, Octavia Combi, etc.

SUV (Sports Utility Vehicle) - These vehicles have large tyres, higher seating, higher ground clearance. The engine area is separate, but the passenger & luggage area are enclosed together. Most of these vehicles are equipped with either 4 wheel drive system or has the option for that. For eg. CRV, SAFARI, GRAND VITARA, PAJERO etc

SEMI NOTCHBACK - Its a sedan whose boot door can be opened like a hatchback (wagon r, swift), where the rear windsheild too opens along with the boot door. Unlike sedan whose rear windsheild is always fixed. There are only few examples for SEMI NOTCHBACK - Skoda Octavia, Accent Viva.

To add the Dzire is NOT a notchback.

But to make things interesting the new Skoda Superb is a 'Notchback Saloon' !!

But dzire is classified as Sedan/notchback.

Hatchbacks still have a boot, but the boot will be accessable from inside where in a sedan it cannot be.

In the dzires brochure, it is classified as notchback

what is the difference between SEDAN and NOTCHBACK???

Anyone please help

As per information i got, both are same, Sedan/Saloon/Notchback...

I've no knowledge, Why these 3 different terms are used?

Sedan & Saloon are same.  Hatchback is 2 box design while Notchback is 3-box (discussed before in post 14).

Here's another - Fastback.