1. The document discusses reusability in object-oriented analysis and design and software engineering. It states that reusability is promoted through frameworks that encourage reusing existing software components rather than redeveloping them.
2. Software engineers practice reusability through reusing expertise, standard designs and algorithms, libraries of classes and procedures, frameworks, and complete applications. Frameworks provide common, reusable facilities for different application programs to build upon.
3. Examples of frameworks discussed are ones for payroll management and e-commerce websites, which could implement common features for different businesses to customize for their individual needs, saving development time.