1. Clinical Psychology: Clinical psychology focuses on diagnosing and treating mental health conditions. 

2. Cognitive Psychology: Cognitive psychology focuses on how people think, remember, and learn. 

3. Developmental Psychology: Developmental psychology focuses on how people grow and change over time. 

4. Educational Psychology: Educational psychology focuses on how people learn in educational settings. 

5. Forensic Psychology: Forensic psychology focuses on the intersection of psychology and the law. 

6. Health Psychology: Health psychology focuses on how physical health and mental health are related. 

7. Industrial-Organizational Psychology: Industrial-organizational psychology focuses on how people behave in the workplace. 

8. Neuropsychology: Neuropsychology focuses on how the brain and nervous system affect behavior. 

9. Social Psychology: Social psychology focuses on how people interact with and influence one another.

Psychology is the scientific study of the mind and behavior. It is a multifaceted discipline, with a broad range of sub-fields that explore the cognitive, developmental, social, and biological aspects of behavior and mental processes. Through research, psychologists strive to understand how people think, feel, and behave and how they can improve the quality of their lives.

The steps for writing a business plan include research, creating an outline, filling in the details, and proofreading. The research phase should involve researching the industry, competitors, and target market. The outline should include the key components such as the executive summary, company description, and financial plan. Once the outline is complete, the details can be filled in. Finally, the plan should be proofread to ensure accuracy and clarity.