hi
i am new to houdini and i'm trying to learn vex to create geometry and to manipulate the position of the points .
i tried looking at the documentation online but i still could not get it . can somebody please suggest me how to learn vex ?
my other quesion is whats exactly geometry handle() ?

Best way to start is look at as many tutorials that use vex as part of their example.

You could start by putting in VEX as your search term in the tutorial section of this website.

You might find Anastasia Oparas' tutorials with vex interesting as she gives good examples that you could start with.

From there after watching and playing around with some tuts with vex I would suggest just thinking of simple projects and posting questions here when you get ‘stuck’.

'Geomtery handle()' …you mean like what you see in the docs on vex functions like - ‘<geometry>geometry’ or ‘int geohandle’ ?

When working with some vex functions with a wrangle you need to specifiy the geometry you are referring too.

This could be which of the wired inputs of the wrangle node you are writting your vex in or even from another node elsewhere in your scene.

Vex in the context your speaking of, although you can find its' use in other places like VOPs and Shaders, is typically used in wrangles.

By playing around with vex your going to have to get familiar with the behaviour of your vex code in the wrangle nodes depending on it's ‘Run Over’ mode.

Points, Primitives and Vertices have the same ‘behaviour’ with exception as to what they are running over.

Detail(once only) is different.

And Numbers has its own scope.

Of course more and more nodes also have the capacity to use vex in their expressions - which can require slightly different syntax that what might be used in a wrangle context - Like not needing to use the ‘@’ symbol to refer to an attribute.

Again, in my opinion, just start with viewing some tutorials that use vex as part of their examples and try thinking of some simple ideas yourself and post for help to progess.