Server Wide Modules
What is Server Wide Modules? Answer: Modules which has to be loaded/installed as server wide. For example: web, web_kanban.
Two Ways to Install Server Wide Modules in Odoo
If you have created apps which has to be loaded has server wide modules then you have to do specific configuration to able to install it on Odoo.
--load=web,web_kanban,custom_server_wide_module option while running server if you do not want to specify on Odoo configuration file (odoo-server.conf).
server_wide_modules = web,web_kanban,custom_server_wide_module