It is usually assumed that in order to have a child, a person needs to be in a couple. While that is a traditional view, it is not necessarily a correct one. Sometimes, a single woman or man who has a professional career and does not want to be in a relationship would still like to have their own children.
So, for people in this category (as well as couples who are having trouble conceiving naturally) fertility clinics are important places to seek out. Say, for example, that a single, professional woman would like to have a child. She will need to search for fertility clinics in her area that offer either artificial insemination, or surrogacy.
In the case of artificial insemination, the woman has the option to be impregnated with the sperm of either a man she knows that has agreed to be a donor, or from a sperm bank. Usually, fertility clinics have a sperm bank as well, and there the woman can choose from many donors. The donors remain anonymous, but basic information about them will be shared, such as their physical statistics (height, eye and hair color), employment, and education.
Single men usually seek out fertility clinics because they are looking for a surrogate. In this case, a woman is fertilized with the sperm of the man, and carries his baby until birth, upon which time he takes full custody of the child. No matter what a man or woman's background, it is very important that they do their research.