By studying both the external and internal environments, firms can identify opportunities and threats as well as their own unique resources, capabilities, and core competencies. Internal analysis focuses on determining a firm's competitive advantages through examining its competencies, capabilities, and resources. Competencies include core, distinctive, strategic, and threshold competencies. Capabilities emerge from resources and allow firms to deploy resources to achieve goals. Core competencies are sources of competitive advantage and distinguish a firm. Building sustainable competitive advantages requires capabilities that are valuable, rare, costly to imitate, and nonsubstitutable. Firms can also analyze their value chain to understand how to create value and identify competitive advantages.