The definition of GLAM as explained in Wikipedia:
GLAM is an acronym for “galleries, libraries, archives, and museums“, although other versions of the acronym exist, such as LAM, which incorporates only libraries, archives, and museums. More generally, GLAMs are publicly funded, publicly accountable institutions collecting cultural heritage materials.
The GLAM-Wiki initiative helps cultural institutions share their resources with the world through high-impact collaborative projects with experienced Wikipedia editors.
This blog complements the many GLAM sites by sharing news and events that GLAMmers will be interested in.
I hope this site is useful to you.