Yeah there are a few fruit / vegetable / berry / tree / herb terminology issues.

Fruit can be used in a botanical sense. In botany, a fruit is the seed-bearing structure in flowering plants, formed from the ovary after flowering.

In common language/culinary usage, "fruit" normally means the fleshy seed-associated structures of a plant that are sweet or sour, and edible in the raw state, such as apples, bananas, grapes, lemons, oranges, and strawberries.

The botanical usage includes many structures that are not commonly called "fruits", such as bean pods, corn kernels, tomatoes, and wheat grains. The section of a fungus that produces spores is also called a fruiting body.

Vegetable in common/culinary usage usually refers to parts of plants that are consumed by humans as food as part of a meal.

This definition is applied somewhat arbitrarily, often by culinary and cultural tradition. It may exclude foods derived from some plants that are fruits, nuts, and cereal grains, but include fruits from others such as tomatoes and courgettes and seeds such as pulses.

The original meaning of vegetable is applied to plants collectively to refer to all edible plant matter, including the flowers, fruits, stems, leaves, roots, and seeds.

In summary:

The term "Fruit" is used in both a cultural/culinary sense, and a botanical sense.

The term "Vegetable" also has two definitions, one cultural/culinary.

If you compare the culinary fruit and the culinary vegetable, it usually neatly divides foods into categories.

If you start bringing in botanical fruits, they will not always fit into our idea of fruit in a culinary sense. Botanical fruits will include some things that are considered a vegetable in the cultural/culinary definition of vegetable.

If you are thinking in the older sense of vegetable, then all botanical fruits are within that category, and all culinary fruits are also all within the category.

Also there is a culinary/common usage idea of what a berry is, but it is different from the botanical definition of a berry. This is where bananas and strawberries come in.

Banana trees are a herbaceous plant, herbaceous plant being a botanical definition.

> Herbaceous plants in botany, frequently shortened to herbs, are vascular plants that have no persistent woody stems above ground. Herb has other meanings in cooking, medicine, and other fields. Herbaceous plants are those plants that do not have woody stems, they include many perennials, and nearly all annuals and biennials, they include both forbs and graminoids.

> Herbaceous plants most often are low growing plants, different from woody plants like trees, and tend to have soft green stems that lack lignification and their above-ground growth is ephemeral and often seasonal in duration.

There is also the general term, "herb".

> In general use, herbs are plants with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal purposes, or for fragrances; excluding vegetables and other plants consumed for macronutrients. Culinary use typically distinguishes herbs from spices. Herbs generally refers to the leafy green or flowering parts of a plant (either fresh or dried), while spices are usually dried and produced from other parts of the plant, including seeds, bark, roots and fruits.

> Herbs have a variety of uses including culinary, medicinal, and in some cases, spiritual. General usage of the term "herb" differs between culinary herbs and medicinal herbs; in medicinal or spiritual use, any parts of the plant might be considered as "herbs", including leaves, roots, flowers, seeds, root bark, inner bark (and cambium), resin and pericarp.

So essentially, the word "herb" is used is two different senses.