Describe sexually transmitted diseases and mention the ways to prevent them.

Explanation

### Step-by-Step Solution:

1. **Definition of Sexually Transmitted Diseases (STDs)**:
- Sexually transmitted diseases (STDs) are infections that are primarily spread through sexual contact. They occur when an uninfected person engages in unprotected sexual intercourse with an infected individual.

2. **Causes of STDs**:
- STDs are caused by pathogens such as bacteria, viruses, and parasites. The transmission typically occurs through the exchange of bodily fluids (blood, semen, vaginal secretions) during sexual activities.

...