Commercial publishers are companies which focus solely on publishing books that are commercially available for purchase. These publishers do not charge fees to authors for publication and typically provide substantial quality-control measures, such as peer- or editorial-review. Commercial publishers are considered reputable and are ideal for academic careers.
Vanity presses or print-on-demand publishers are not commercial or academic publishers and are often not considered reputable in academic careers. Some may also be considered predatory publishers. Here are some characteristics that may help to spot vanity presses.
Publishing with a vanity press may result in considerable financial cost, loss of copyright to your work, and damage to your academic reputation.
The following resources may be useful if you are considering turning your thesis into a monograph.