What differences exist between cost accounting and managerial accounting?

They are explained very thoroughly in these old posts. Why don't you read them, and if it's still unclear let us know and we'll try to explain it again.

https://www.askmehelpdesk.com/accounting/what-difference-between-managerial-accounting-cost-accounting-167546.html

https://www.askmehelpdesk.com/finance-accounting/difference-between-management-accounting-cost-accounting-310293.html