Spices are meant to be used almost in the same capacity as herbs. They contribute flavor mostly, and on some occasions they contribute texture, but this is not a desirable quality. Spices tend to be on the hard side and are generally unpleasant to chew on, let alone swallow. Spices can be toasted before they are used to increase their strength. Heat releases the aromas that are particular to a spice; when using them raw (that is, not toasted), they are not as flavorful. Spices can be combined with other spices to produce successful and appealing flavors, but it is important to know how to use them in combination for the results to be harmonious. One spice can easily overpower another one if they are not used in the correct proportion.