I have seen aura:component attributes like renderer and support.. But the following link does not mention these attributes.. Aura Component Doc What am I missing here? Also what is the difference between global and public access specifier?
The documentation you linked describes the access specifiers:
access] Indicates whether the component can be used outside of its own namespace. Possible values are public (default), and global.
To be clear, a component must be
global to be used outside of its own namespace. Components that are not part of a namespace you define have the pseudo-namespace
c, as in
The renderer is one of the elements of the Lightning component.
Based on your comment, it sounds like you're looking at the source view of some of the core Aura framework components. Note that neither attribute is documented as part of the public "shape" of a component even at the Aura level - they're internal to the framework.
In that context,
support="GA" translates to "Generally Available". I can't say as I understand the Aura framework at a deep enough level to explain the mechanisms of the
renderer attribute, but since it's connected to the server-side Java framework and not documented as part of the interface of an Aura or Lightning component, it's not something you have to deal with building your own Lightning components. The framework is responsible for "auto-wiring" your components' renderers, should you choose to create them, to ensure they're used appropriately.