About camera & its lens?

I'm planning to buy a canon DSLR camera which comes with, 35mm lens, as the lens are expensive can i use the other brand lens such as, Nikon, Sony or any other. Will all the camera come with the same type of lens fitting ( i mean the size of the lens to fit in the body of camera)?

No. Each camera's lens mounting system is unique to that brand. There are adaptors available but you'd be much better off using Canon lenses on Canon cameras.

The great thing about Nikon, if you decide to go that way instead, is that the mounting system is universal to all Nikon DSLR cameras/lenses. This means, you can purchase a Nikon lens that is 20 years old and it will still work

No.

Nikon, Sony and Pentax lenses won't fit the Canon dSLR. Those are major camera brands. They have their own propriety mount which are not interchangeable among different brands. They are neither cheaper too and some will even be more expensive than the Canon version.

Cheaper means getting third-party brand lenses. Among them, Tokina is the best. Sigma and Tamron are also popular and priced lower. Just to clear things up, get the same mount as your camera. These companies make lenses for all camera brands. Be very specific with the lens mount. Get only Canon mount lenses.

As contributor "Jim A." says lenses are specific to the brand.i. E. Canon fits only Canon, Nikon only fits Nikon, and Pentax only fits Pentax. In Canon & Nikon's case the manufactures designed their lenses to incorporate the "stabilization" feature. However Pentax took a different approach and that is the stabilization feature is built into the camera body not each lens. This enables the Pentax's DSLR's to accept older lenses even back to film days. Older lenses are of course used and their is a bigger market of used lenses. However you need to be careful as a few of the early lenses do not have automatic diaphargms (f/stops-iris diaphagrm) and you will have to set the f/stop manually for each shot.
I was a Canon user from high school to retirement. I did not like the viewfinder in the Canon DSLR's because of the 5 focusing squares drove me nuts! I purchased a Pentax DSLR with the standard zoom 28-55mm and then added a 50-200mm. BUT had I bought both together in kit form I would have saved $50.00! So a word to the wise. The current Pentax is the Pentax K30 priced @ $600.00, but in kit form with the 50-200mm lens added it is priced at $800.00-a great deal!

A good lens is more important than a DSLR. If you are trying to cheap out on lenses, your final result will be mediocre. You may want to re-think this DSLR thing.

All camera manufacturers use a proprietary lens mount so there's no compatibility between brands with the exception of Olympus and Panasonic who collaborated on the 4/3 lens mount and now the Micro 4/3 lens mount.

Nikon lenses fit Nikon bodies.

Pentax lenses fit Pentax bodies.

Sony lenses fit Sony bodies.

Olympus and Panasonic lenses fit both bodies.

Canon lenses fit Canon bodies.

Something to think about: Nikon and Pentax have the best backwards lens compatibility. Nikon has used their "F" lens mount since 1959 and Pentax has used their "K" lens mount since 1975.

Something else to think about: Both Nikon and Canon offer crop-sensor DSLR cameras and full-frame DSLR cameras. Both Nikon and Canon offer an economy line of lenses designed for their crop-sensor cameras and a professional line of lenses designed for their full-frame cameras.

However, a Canon "EF-S" lens intended for their crop-sensor camera Can't be used on a Canon full-frame DSLR. A Canon "EF" lens can be used on a full-frame or crop-sensor camera.

Nikon designates their lenses as "DX" for crop-sensor cameras and "FX" for full-frame cameras. Unlike Canon, though, Nikon designed their "DX" lenses so that they CAN be used on their full-frame cameras. All the user of a Nikon full-frame camera has to do is go into a menu and "tell" the camera a "DX" lens will be used and the camera automatically "crops" the sensor to the size of a crop-sensor camera.

Regardless of what camera you buy I strongly suggest getting it with the usual 18-55mm zoom. You will find this lens far more useful and versatile than a 35mm prime lens.