ACCA is general accounting, auditing and financial services. It is applicable for all areas of accounting, including management (costing) and financial accounting.
CIMA is specifically for cost/management accounting. You learn costing and management accounting skills at a more indepth level than with ACCA.
While ACCA allows you to functionin any accounting role, CIMA is more specific in the roles in which you will be competent to perform in. It should be said though that depending on your career goals, you may not be disadvantaged by pursuing CIMA instead of ACCA, but you need to deceide what your aim in life is.