Dialect, which is similar to jargon, is well known if not often thought of. When looking at a person one might notice his clothes, features, size, mannerisms, but will not realize whether or not he uses dialect or jargon until he opens his mouth and speaks. Unlike outward appearances, it may be kept hidden, if a person chooses to do so. Just because a person may be heard using dialect or jargon at times does not necessarily mean that they stick to that language all the time, or forever. It may be on a short term basis that one uses either of them, or even at particular times. A doctor or nurse, who uses jargon all day at work, probably wouldn't go home and use the same terms used at the hospital when speaking to his/her young children. On the other hand, some people, such as a great number of residents in the south, speak in a particular way, usually referred to as "country", and never take a break from their way of speaking, continuing to speak in their accustomed way all the time, whether at home, work, or wherever else they may be. This is a good example of dialect. .
Dialect is also capable of being able to make two people feel as if they can "read each other's minds". Or if two people have just met, it can make them feel as if they "speak the same language". And in fact, they do, to an extent. People display a lot of different meanings in the way they communicate, their accents, and sometimes the body language they use. Interesting enough as it is, you can often tell several things about a person by these characteristics. For example: their origin and sometimes the community they reside in although it's not their homeland.
One example of people using dialect is the elderly people who are native to the Appalachian region. I am not the first to notice this, as there have been countless books written about their way of life, but I do have first hand knowledge, being from this area and having elderly grandparents who are perfect examples.
