Antiviral agents are medications designed to treat viral infections by inhibiting the development and replication of viruses. They work by targeting specific stages of the viral life cycle, which can help reduce the severity and duration of illnesses caused by viruses such as influenza, HIV, and herpes. These agents can be classified into different categories based on their mechanisms of action. Some antivirals block viral entry into cells, while others prevent the virus from replicating or assembling new viral particles. Common examples of antiviral agents include oseltamivir for influenza and acyclovir for herpes infections.