Mitosis: This is the process where a single cell divides into two identical daughter cells. It's like photocopying an entire book so you have two copies.
Photosynthesis: This is the process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll pigments. It's like cooking food using solar power.
Respiration: This is the process by which cells break down simple food molecules such as glucose and release the energy they contain. It's similar to burning fuel in a car engine to generate power.