The old definition (according to Wikipedia) for the term Alumni has always existed with reference to an individual's alma-mater:
“A former student who has either attended or graduated in some fashion from an educational facility”
The term has now broadened to include anyone who has had an affiliation of some form with an organization - i.e. not only educational facilities, but it now includes affiliations with corporate or non-profit entities. It also no longer has to be someone who used to work full-time for that organization: it has expanded to include part-timers, interns and volunteers.
The evolution of the term reflects the changing business environments in which organizations are keen to maintain a relationship with anyone whom they have had a formal relationship with, as each segment of Alumni can provide differing values - whether it be interns converting to employees, retirees providing knowledge transfer, or volunteers as brand advocates.
An Alumni Platform is a web-based application to enable organizations to manage and engage their Alumni community. It provides organizations with the opportunity to leverage this community to drive various business objectives.
As organizations expand their definition of what it means to have a formal relationship, as the gig-economy expands and as the need to expand a talent pool increases, the term Alumni will gradually equate to the term “Community”. Their Alumni Platforms will become Community Platforms that enable anyone with a relationship to stay connected.
A job applicant that didn’t get the job, the spouse of an existing employee keen to explore opportunities for their children or access discounts, or contractors who want to continue taking advantage of the learning programs and remain eligible and active for future contracts.
As a recent Corporate Alumni Survey reflected, organizations' Alumni are already expressing their desire to be involved in more than just a “recruitment/candidate” conversation, for example whether that's to amplify a sustainability project, be a part of an internal Employee Resource Group around diversity, or any other employee-led topic.