Concept:
Corticosteroids are steroid hormones or synthetic steroid drugs with strong anti-inflammatory and immunosuppressive actions.
Step 1: Inflammation involves swelling, redness, pain, and release of inflammatory mediators.
Step 2: Corticosteroids reduce the formation of inflammatory mediators.
Step 3: They suppress immune responses and inflammation.
Step 4: They are used in asthma, allergic reactions, autoimmune diseases, and inflammatory disorders.
Step 5: Therefore, corticosteroids are mainly used as anti-inflammatory drugs.
\[
\boxed{\text{Anti-inflammatory drugs}}
\]