texture memery and define texture

hello i want to know whethe when we define a 3d texture llike glTexImage3D(GLenum target,Glint level, Glint internalFormat, GLsizei width,GLsizei height, GLsizei depth, Glint border,GLenum format ,GLenum type, const GLvoid *texels); then the *texels will be put into the texture memery?

The image will be put wherever the driver thinks is best. Video memory? Probably. Somewhere else? Maybe. It depends. But likely, it will end up in video memory.