Public Art Gallery
A public art gallery differs from a museum in that there is no conservation of works and no on-site storage space. There is no permanent collection here. It is a temporary exhibition space where new works are opened immediately after the event. Rotating displays lead to many discoveries and possible publications.

Private Art Gallery
The commercial activity of a private art gallery is to sell works and promote the artists it usually represents under contract. A gallery can use various means to sell works and promote its artists: it can hold exhibitions in its own space or in other locations if it does not have a suitable space, or it can exhibit in a certain way the virtual online objects that it promotes. It can publish booklets, brochures and/or catalogs about its artists. Some galleries act as publishers and publish collections of monographs, surround themselves with suppliers to do multiple copies (prints, bronzes, etc.).

It is run by a gallerist, equated to the profession of art dealer, considered an intermediary between the artist and the buyer.

Sale
The gallerist sells his works locally, nationally or internationally. The gallerist advises buyers on a daily basis to sell the work of the artists they support. During events – openings, conferences, meetings – he invites a target audience of professionals, collectors or museum representatives. To spread the work and make it known, the gallery usually has documentation of the artist and exhibition, sometimes with a bookstore department. Rarely displayed, prices are always available upon request.

Depending on their size and turnover, they are, in principle, able to give advice and guidance and are a reliable source of documentation if they work in an environment of recognized experts. It is often conducted by a passionate, competent, often specialized person with whom the visitor can talk.

Works of art offered for sale come from:

Either a deposit made by the artist for a specific period;
or stock resulting from the purchase of works or the exchange of services. For example, if a gallery helps an artist produce a publication, the gallery owner usually receives a commission from the artist for free copies.
Galleries can be divided into two categories: shopping centers that operate primarily by purchase-re-sale, and galleries that discover, support and, in some cases, participate in the artistic achievements of the artist.

In both cases, they support the logistics and administration, namely the organization and installation of exhibitions, insurance, accounting, storage, packaging and delivery of works.