benefits of react, state management, life cycle, prop drilling, hoisting, reduce/filter/map, var/let, event bubbling, virtual dom, deep and shallow copy, hooks , useContext, useMemo, useCallback, states in promise, normal and arrow function, accessor and mutator, final keyword, interface & abstract, traits, orm benefits, relationships in model, facade, factory, migrations & seeders, crons, jobs, events& listeners, service provider, service container, dependency injection, dependency inversion, magic methods, csrf, xss, sql injection, indexes, query optimisation, joins,