Screening technologies are at the heart of drug discovery research. Because screening is so important for identifying and validating targets, the quality of the screening technique used can make or break whether a new drug makes it to the clinic. A variety of methods are used to find chemical compounds that can be manufactured and marketed. The complexity of drug development has increased dramatically in the last 40 years. Drug discovery is the process of discovering new drugs. Drugs were previously discovered primarily through the discovery of active ingredients in traditional medications or by chance. To limit potential drug side effects, drug discovery nowadays entails hit screening, medicinal chemistry, and hit optimization (increasing affinity and selectivity). Efficacy or potency, metabolic stability (half-life), and oral bioavailability are all improved during the stage of the drug development process.