Herbs can be preserved in a variety of ways for use at a later date, thus allowing you to use herbs that may not be freshly available. How the medicinal properties of herbs are extracted and preserved are dependent on the solvent (liquid) used, and what purpose that the herb will be used for. For examples, alcohols can extract resins from plants, and water is used for mucilages.
Elixirs or syrups are sweet infusions used for medicinal purposes. Examples of such liquids are honey, glycerin, brandy, and maple syrup. They are medicinally not as potent as a tincture made with alcohol, but can be useful for simpler tasks such as an digestif.