Herbs are plants that are grown either as a food (usually as a condiment), or because they have some use in treating diseases (or making them better), or for spiritual reasons (for example, their smell).
The word herb comes from the Latin word herba, meaning grass, green stalks, or blades. Botanists use the word to mean any plant with soft, succulent tissues. But many people use the word to mean only herbs with some economic value.