This document discusses different types of injections administered for medical purposes. It describes intradermal injections which are administered just below the epidermis and have the longest absorption time. Examples of medications given via intradermal injection include Botox and tuberculosis vaccines. Subcutaneous injections involve administering medications into the subcutaneous tissue using a needle. Common uses of subcutaneous injections include insulin, blood thinners, vaccines, and pain medications. The document outlines four main types of injections: intradermal, subcutaneous, intramuscular, and intravenous.