Quick answer

Both are fee-based, cost-reimbursable management routes for large projects needing an early start, and the key difference is that a management contractor holds the contracts with the works contractors, whereas under construction management the employer contracts directly with each trade contractor

Both are procurement routes for large projects that need an early start before the design is complete, and in each a manager is paid a fee while the work is done by others under a cost-reimbursable arrangement. The difference is who holds the work contracts. Under management contracting the management contractor engages the works contractors and is in contract with them, managing and supervising their work; under the common standard form a works contractor's default does not fall on the management contractor. Under construction management the construction manager only manages, and the employer contracts directly with each trade contractor, so the employer holds the relationships and must bring any proceedings against a trade contractor itself. The allocation of package default, overrun and inflation risk depends on the appointments, work contracts and any express caps or guarantees.