Add restriction to content on the basis of various User I am new in drupal, So I want to know how can I restrict my content in content listing according to various users. e.g. I have four contents named A,B,C,D. Now I want Customer1 to see and edit only content A and B. While Customer2 can do the same with C and D only.
I've done my research and read about "form_node_admin_content_alter" but not sure how it works. So kindly provide me an efficient solution for this.

Thank you
Creat role and assign role to the different user. Based on role set permissions of view content under people permission page.

If A role user can see A type of content so you can allow permission to view that content type page.