A sociolect it's a kind of dialect : a linguistic structure that derives from another and that is usually bounded to a certain group, but that lacks the differential characteristics necessary to separate it from other structures of the same origin.
It can be defined to a dialect, therefore, as a linguistic variety which is characterized by its traits shared by a community . In other words, a dialect is a particular form of a language .
With all this clear, we can move forward with the definition of sociolect . It's about a social dialect : a variety of language that employs a certain class or a social group . The social groups, when developing their speeches, appeal to a sociolect whose members share and allow them to communicate with each other and, sometimes, with others.
Clear examples to understand the term sociolect would be the following:
-While in some social groups it would be said “We have been shopping”, in others the same would be expressed as follows: “We went to stores”.
-While in one social group you can use the expression "we are compadres", in another you would bet to indicate the same saying "we are friends".
-If in a social group to indicate that you do not have money, you would say “I do not have a parne or I do not have a guy”, in another one you could say “I have a visa to zero” or even “I do not have cash”.
Since the sociolect is shared by a group of the society , the rest of the members of the community may not understand some terms and expressions used by speakers. There are cases in which certain words of a sociolect ended up becoming widely used words and incorporated into the natural language.
Let's take a example of sociolect. A lower-class Argentine teenager could tell another: "Look at the tires of that guy: sure they cost an egg". A young man from another social class, on the other hand, will pronounce the same idea as follows: “Look at the shoes of that boy: they sure cost a lot of money”. Terms like "Tires" and "Good-bye" and the expression of "Costs an egg", therefore, they can be associated with a particular sociolect as they are employed by a social group.
It is also important to establish that, sometimes, what is sociolect is often confused with idiolect. However, it should be borne in mind that the latter does not refer to the language used by a social group but to that used by an individual, that is, it is the characteristic way each person has to express themselves. And that means that you have your phrases, your tone of voice, your expressions, changes or turns in pronunciation ...
However, that does not take away so that, sometimes, through the aforementioned idiolect you can be clear or, at least, intuit to which social group the individual in question can belong.
It must also be said that when referring to the way of using the language that the same individual uses when writing, then more than idiolect, the term style is used.