Hotel technology glossary: PMS, API, channel manager and more

A hotel technology glossary defines the words vendors use to describe hotel software: the PMS runs the property day to day, an API lets two systems exchange data, and a channel manager keeps rates and availability aligned across the places a room is sold. Each term earns its place only with a question that tests the claim behind it.

A vendor deck says the product is live, fully integrated and multi-tenant. Three words, three claims, and no way yet to tell which of them your hotel can actually check. This hotel technology glossary gives each term a plain definition, an example of it at work in a hotel, and the question that turns the label into something verifiable. After reading, you will be able to take any vendor document and mark the words that carry claims, then ask for the sentence behind each one.

How should you read a hotel technology glossary?#

Read every entry in three steps: the plain meaning in one or two sentences, a hotel example that shows the term at work, and the question that tests a vendor's use of the word.

The word itself is often the claim. A vendor that writes "live", "integrated" or "single source of truth" is making a statement about the software, and the glossary exists to turn that statement into something you can verify. Keep one term for one concept: if a supplier uses "PMS" and "hotel operating system" as if they were the same, ask which one they mean, because the second is a wider scope than the first.

In Turkish daily use the PMS is also called "otel otomasyon programı". Both names describe the same core system, so use whichever your team uses and translate once for the record. Prefer the plain word throughout: if a term cannot be explained in two sentences by the person selling it, the hotel will carry the cost of that vagueness after signing.

Treat this page as a working list, not a dictionary. Terms change meaning between vendors, and the question matters more than the definition. Words about AI, such as assistant and agent, are deliberately left out here and covered in a separate glossary for hoteliers.

What is the difference between a PMS, a CRS, a booking engine and a channel manager?#

They hold and move different things: the PMS runs the property, a CRS holds rates and availability centrally, a booking engine sells on the hotel's own website, and a channel manager keeps the same room from being sold twice across sellers.

The PMS (property management system) is the operating record of the property. HTNG, the hotel technology network of the American Hotel & Lodging Association, describes it as the primary interface for guests, reservations, folio and room data, and notes that integrations with the PMS are generally lengthy and complex (AHLA/HTNG, HTNG Completed Workgroups, November 2026 (opens in a new tab)). A hotel operating system is the same core with a wider scope, adding billing, housekeeping, restaurant sales, reports and compliance in one place. The difference from a PMS is scope, not age; what changes in daily work is the real test of the wider claim.

The remaining terms divide the work of selling rooms. A CRS (central reservation system) holds rates and availability for several properties, usually a group or chain; a single hotel may never need one. A booking engine turns a visit to the hotel's own website into a reservation: it reads inventory, it does not own it. A channel manager sends rates and availability to the places a room is sold and brings reservations back, so two guests are not promised the same room. At the outlet level, an ÖKC fiscal device is the cash register; connecting a device is not the same as issuing an invoice, and an e-Arşiv invoice is a separate electronic document (GİB, e-Arşiv Fatura Hakkında, 2026 (opens in a new tab)).

Ask which system is the master for a rate and for a reservation. If two systems both claim it, you have found the first question of the project.

What does "integrated" actually mean?#

It means two systems exchange data automatically. The words that follow tell you how, how fast and how safely, and those are the words worth checking.

An API (application programming interface) is a defined list of requests one system is allowed to make to another. Think of a menu with fixed items, not an open kitchen. Polling is one system asking the other every few minutes whether anything has changed: simple, and always slightly behind. An event is the opposite: the source system tells subscribers when something happens, such as a check-in, a check-out or a room going out of service. HTNG's Event Notification Specification sets out this publish-and-subscribe method (AHLA/HTNG, version 3.0, 24 April 2015 (opens in a new tab)).

Three supporting words decide whether the connection survives contact with reality. A version is a numbered form of an interface; a versioned interface can change without breaking the partners already connected to it, so ask what happens to your connection when the version moves. OAuth 2.0 is the common way an application obtains limited access to a service and states the scope it is asking for (IETF, RFC 6749, October 2012 (opens in a new tab)): in plain words, a permission slip with a stated limit. A test environment is a copy of the system where the connection is tried before real guests depend on it; ask to see it, and ask what was tested in it.

For electronic invoices there is one more word. The Revenue Administration lets taxpayers use the tested system of a special integrator authorised for this purpose and publishes the list of those institutions (GİB, e-Fatura Özel Entegrasyon, 2026 (opens in a new tab)). In plain words, a licensed intermediary.

To see how these pieces sit next to each other in a whole stack, read how the core systems of a hotel technology stack fit together.

What do single source of truth, multi-tenant, export and backup mean?#

These words describe where the data lives, who else shares the same system, and what you can get back out of it.

A single source of truth is one record that every other system reads. Test it by asking which system is the master for a room rate, and which is the master for a reservation. If the answers differ by topic, that is normal; if the answers differ by who you ask, that is a problem.

Multi-tenant means several customers served from pooled computing resources. NIST describes resource pooling as a multi-tenant model in which customers generally have no control over the exact location of the resources, though they may be able to specify location at a higher level such as country (NIST, SP 800-145, September 2011 (opens in a new tab)). Multi-tenant does not mean shared data: separation between hotels is a design decision, so ask how it is done rather than whether the system is "secure".

The last three words are about getting your data back. Export means whether you can take reservations, guest records and financial data out in a usable format, how often, and at what cost; ask before signing, not after. Retention means how long records are kept and why, and it interacts with personal data duties, so confirm your own periods with a legal adviser. Backup means how often, where, and how a restore is tested. A backup that has never been restored is a plan, not a fact.

What do built, tested on sample data, pre-production and live mean?#

They describe how far the software has travelled, and each one excludes something specific.

Built means working software, ahead of launch, not yet in customers' hands: real code, no live guests. Tested on sample data, sometimes called fixture-tested, means the connection or feature works against prepared data; it has not yet met the other party's real system. Pre-production means running against the real counterpart in a test setting, before general availability: closer to live, still not live. Live means operating today with real guests and real money, so ask for the sentence behind the word: which functions, since when, and for how many properties.

"Certified" is not a status. A certificate names a body, a scope and a date, so ask which certificate, issued by whom, covering what, and read the scope rather than the badge. Watch for the adjective doing the work of a sentence: "fully integrated" and "live" are claims a hotel can ask to see demonstrated in a test environment. Before your next vendor meeting, review the questions to ask hotel PMS vendors in Türkiye.

What do permissions, logs and tamper-evident mean?#

They describe who may act, what is recorded when they do, and how far that record can be trusted later.

Permissions define who can see and do what. Ask for the list of roles and for the two that matter most: who can change a rate, and who can void a bill. A permission that can be changed without leaving a trace is not a control, so ask whether role changes are recorded and who can make them.

A log is a record of what happened and when. Many systems let an administrator edit or delete a log entry, which is why the next term exists. Tamper-evident means past records can only be appended, and if someone alters one, the chain shows it. It is not the same as a record that cannot be changed, and it should never be described that way.

Ask to see one sample record from a past day, with the person, the time and the change. A record you cannot read is a record you cannot use in a dispute. Keep the distinction in your notes: a log tells you what the system did, a reliable record tells you what the system did and whether anyone touched the account afterwards.

Which fiscal and guest-data words appear in the same meeting?#

The invoice words, the guest identity words and the personal data words usually arrive together, and each one carries a duty that belongs to the hotel, not to the software.

e-Fatura is the electronic invoice exchanged between taxpayers registered for the system. e-Arşiv is an invoice created electronically and delivered to the buyer on paper or electronically, as the buyer asks; it is issued to buyers who are not registered for e-Fatura (GİB, e-Arşiv Fatura Hakkında, 2026 (opens in a new tab)). An integrator is the authorised intermediary whose tested system sends and receives electronic invoices for taxpayers whose own systems are not sufficient (GİB, e-Fatura Özel Entegrasyon, 2026 (opens in a new tab)).

KBS (guest identity notification) is the identity notification made for guests at check-in; describe it as a duty of the lodging facility and leave the operational detail to your adviser. KVKK (personal data protection law) covers consent, retention and the rules on transferring data: the software can hold the fields, the duty stays with the hotel. The ÖKC fiscal device is the cash register at the outlet, and which outlet needs a device, an e-document or an invoice is a question for your accountant, not for the vendor's brochure.

A vendor may support these duties without carrying them. Ask what the software prepares, what a person must review, and what the hotel signs.

What to do next#

Take the vendor material you already have, circle the three words doing the most work in it, and ask for the sentence behind each one: what it means, what was tested, and what the hotel sees when it fails. Then use the hotel technology stack overview to see how the systems fit together, and the PMS buying questions to turn the answers into a shortlist.