Research activities rely on access and repeatability of results. Accurate identification of the subject of the research as well as of the techniques and methods used is critical to obtain reliable results. The adoption of Permanent Unique Identifiers, and specifically Digital Object Identifiers (DOIs) promotes access and reusability of data in modern research. The webinar begins with some basic concepts on Permanent Unique Identifiers. Next, DOIs are introduced describing how they are managed, how they can be obtained and how their features can be of benefit to researchers in a wide range of fields.