Compost can be used as a growing medium by itself, for example, in pots, plant containers or raised beds. You can buy compost for this purpose from garden centres or compost suppliers, and a wide range of suitable options are available, depending on what you want to use it for. For example, mushroom compost, or mushroom and manure compost are very good options for growing vegetables in raised beds. Mushroom compost consists of composted straw and animal waste that has been used for growing mushrooms, and then treated to destroy any spores. Mushroom and manure compost consists of mushroom compost with added manure. Both of these therefore have plenty of organic matter and nutrients suitable for vegetables.
You can also use compost as a soil improver in gardens or on allotments. Adding organic matter to soil has long been recognised as a way to improve soil structure, whether the soil is silty, clay or sandy. Whatever the structure, the organic matter seems to make the soil closer to the ideal soil, loam, with its mid-range particle size, close-to-neutral pH and good but not excessive drainage. You may consider it a bit extravagant to buy compost just to add it to your soil, and many gardeners choose to use farmyard manure for this purpose. However, if you’ve made your own compost from kitchen waste, it can feel very satisfying to use it to improve your garden beds, especially if it’s to grow vegetables!