Social anxiety disorder, also known as social phobia, is a type of anxiety disorder that induces weakening fear and anxiety in social situations. People experiencing this disorder fear attending social gatherings, meeting new people, engaging in small talk, etc. They are scared of being judged or criticized. This is entirely different from being shy or nervous. E.g., all of us face a certain degree of nervousness when meeting someone new or going for an important interview. This nervousness is comparatively easier to deal with. In the case of social phobia, this anxiety is extreme and has the capability of causing disruptions in daily interactions and activities.
Social phobia can be treated through professional help. One can even take steps to help themselves based on the intensity and frequency of symptoms.