It could be said that many experience this type of anxiety in one form or another. However for the people who truly suffer from this disorder, it may severely consume their life to the extent that they may not be able to live their life. This social anxiety can come in different severities. For some, it will be extremely debilitating and for others, it will only affect certain aspects.
It can affect a range of areas in life and situations. For example: speaking in front of people, talking to strangers, speaking on the phone, avoiding eye contact, hating criticism, having low self esteem and so on. It can affect a range of things and there are definitely more aspects and situations than I've just mentioned. Sometimes, it can also lead to panic attacks, and I have written a post on this, here.
I'm writing about this as I have experienced social anxiety in one form or another. For me, it did and sometimes still does affect aspects of my life. I still struggle fairly severely with picking up the phone and talking to a stranger, I.e ordering something, or asking for information. Until recently, I used to hardly look people in the eye when speaking to them. It was even at the point where I would wear dark clothes and no make up in the hope that no one would look at me or would bring my attention to myself.
I know social anxiety can make life just that little bit more difficult, with you thinking about what people will think of you and it affecting the places you go and the people you meet. You're not alone; this is the most common type of anxiety disorder.