Programs that offer a telephone service that enables people who are troubled to talk confidentially about their personal problems with an empathetic listener. These programs are often staffed by volunteers who can offer referrals for ongoing treatment, if needed.

Programs that provide information about specific health and health-related topics including diseases and conditions, birth control, alcohol and drug abuse, mental health, safety and other similar topics that interested individuals can access on a website or in person, or by telephone, email, chat, text or other communication channel. Information may be in a self-serve, browsable format (for example a web resource directory or library of audio recordings) or provided by live agents with expertise in the field.

Individuals who are generally between the ages of 18 and 25 depending on the ages that specific programs use for qualification.

Any of a broad group of malignant neoplasms which are either carcinomas which have their origin in epithelial tissues or sarcomas which develop from connective tissues and those structures which had their origin in mesodermal tissues (the muscular, skeletal, circulatory, lymphatic and urogenital systems and the linings of body cavities). Cancer is invasive and tends to metastasize to new sites spreading directly into surrounding tissues or through the lymphatic or circulatory systems.