The simplest example of a vertex buffer is one that only contains position data. It can be visualized like the following illustration.
More often, a vertex buffer contains all the data needed to fully specify 3D vertices. An example of this could be a vertex buffer that contains per-vertex position, normal and texture coordinates. This data is usually organized as sets of per-vertex elements, as shown in the following illustration.
It's been a while since I've done any modelling, but I do seem to recall that any Sketchup version higher then version 7, outputs the DAE format differently, and Xpacker has trouble reading it.
There was no need for that language in a public forum.
I have reported you @Nahuel Aquino, enjoy your time in Simberia & consider how YOU would feel after giving advice & being treated & 'spoken' to in such a manner.