Differentiate between active immunity and passive immunity.

Explanation

### Step-by-Step Text Solution

**1. Definition of Immunity:**
- Immunity is the body's ability to resist or defend against foreign substances, such as pathogens (bacteria, viruses) or toxins.

**2. Active Immunity:**
- **Development:** Active immunity is developed when a person is exposed to a pathogen or antigen. This exposure can occur through infection or vaccination.
- **Mechanism:** The immune system responds by producing its own antibodies and memory cells that provide long-term protection.
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