what is ' Gelatine '....

Aarthy Sriram asked whether , gelatine is taken 

from animal fat, isnt?

Gelatin plays a key part in both culinary and nutritional
aspects of those not on a vegetarian diet; however, a number
of vegetarians and all vegans choose not to consume gelatin
in any form. This leaves vegetarians with an ingredient
gap when a recipe requires a thickening or gelling agent.
Gelatin is not vegetarian but agar and pectin are. Gelatin
(or gelatine) is a translucent, colorless, brittle (when dry), tasteless solid substance, derived from the collagen inside
animals' skin and bones.  It is commonly used as a gelling 
agent in food.
Gelatin (US spelling) or gelatine (British spelling) is used
to make Jell-o and other desserts  is made from the boiled
bones, skins and tendons of animals.
An alternative substance is called Agar-Agar, which is 
derived from seaweed. Agar-Agar is sold in noodle-like 
strands, in powdered form, or in long blocks, and is 
usually white-ish in color. 
So the question is..
As a vegetarian, if one  don’t use gelatin.
But  don’t know what to substitute when come across it
in a recipe. The answer could be try using..
There are a number of vegetarian-appropriate setting
agents on the market .
Among them agar-agar (powder, strips, or flakes from
a sea vegetable), arrowroot (a starchy powder from the
tropical tuber of the same name), guar gum (the product
of East Indian seed), Xanthan gum (a corn extract), kudzu
(a starchy powder from the plant’s tuber), and certain 
ground nuts and seeds. Most (but not all) kosher gelatins
are also vegetarian. Follow the directions on the package
to see that your food sets up correctly.
For best results, grind the agar-agar in a coffee grinder 
or food processor and then cook it, stirring it regularly 
until it dissolves. When used in a recipe, agar-agar sets 
in about an hour.
Substitute powdered agar-agar for gelatin using equal
amounts.
Agar- agar  has the same effect as gelatin. It comes
from seaweed and has no flavor in and of itself, takes
the flavor of the dish well.
Many kosher gelatins are vegan. Soy-based gelatin
can be used as a  alternative.
Try using pectin to thicken jams and jellies.
A rice starch alternative to gelatin could also be used.
Luckily, there are plenty of easy gelatin alternatives 
available in the market.