Hello all,

I've got two good resources for starting OpenGL both using the C++ language: 
https://learnopengl.com/
and  
OpenGL Programming Guide 9th Edition

The former starts teaching by OpenGL ver 3.3 and the latter by 4.5 while both call themselves teaching "modern OpenGL"!!
At the time being I'm reading both. But I wanted to ask you that while there is distance between 3.3 and 4.5 first which one is correct to be called modern? And which one is better for starting as a beginner?

Thanks. 

Both are modern. Modern OpenGL refers to the use of shaders instead of the fixed-functions pipeline.

I'd say to focus on OpenGL 3.3. First, you probably won't be using the cutting edge features. Second, they have a lot of features in common, which means that 3.3 to 4.5 are very similar in what is needed in general, and you won't have a big problem if you decide to go with 4.5 later. However, since 3.3 doesn't have that "noise" (features that you won't use), it's easier and faster to learn.

OpenGL 3.3 is quite a holy grail for getting rid for definitive of the old OpenGL fixed-functions pipeline and being more consistent with recent versions (4.5).

Thank you for your guidance. 

18 minutes ago, Hodgman said:

If the 3.3 book was written back when 3.3 was the latest version, then it would've been the most modern at the time...

And 4.5 would be post-modernist, today