The new CCNA Composite Exam is an associate level exam that can earn you the CCNA certification. It covers basic concepts and technology on networking, switching and routing using Cisco devices. The new 200-310 DESGN Exam covers new design topics such as the PBM process, NBAR, Netflow, Virtualization ...etc. The two exams share quite many common topics. Therefore it makes sense to study both together.