What are the differences between #version 330 and #version 330 core?

Question

What are the differences between #version 330 and #version 330 core ?

Does the core matter?

Answer 1

Those two version declarations are equivalent. core is the default. From the GLSL 3.30 spec:

If no profile argument is provided, the default is core.

Which means that:

#version 330

is the same as:

#version 330 core

If you want to use the compatibility profile, you need to specify that explicitly with:

#version 330 compatibility

Answer 2

I would suggest reading this: https://www.opengl.org/wiki/Core_And_Compatibility_in_Contexts