There isn't a universally accepted system for classifying fruits into just three basic types. Botanically, fruits are defined as the mature ovary of a flowering plant, containing seeds.

However, we can broadly categorize fruits based on their structure and development:

1. Simple Fruits: These develop from a single ovary. This category is further divided based on how the ovary develops:

- Berries: Have a fleshy ovary wall (pericarp) that encloses multiple seeds. Examples: grapes, blueberries, tomatoes.

- Drupes: Have a fleshy outer layer, a hard stony endocarp (pit), and a single seed. Examples: peaches, cherries, olives.

- Pomes: Have a fleshy outer layer and a core containing several seeds. Examples: apples, pears.

- Legumes: Develop from a single ovary and have seeds within a pod. Examples: peas, beans, peanuts.

- Nuts: Are the hard, dry fruit of a tree or shrub. Examples: acorns, walnuts, hazelnuts.

2. Aggregate Fruits: These develop from multiple ovaries in a single flower. Examples: raspberries, strawberries, blackberries.

3. Multiple Fruits: These develop from the ovaries of multiple flowers clustered together. Examples: pineapples, figs, mulberries.

While these broad categories aren't perfect, they provide a starting point for understanding the diversity of fruits.