# Introduction

Korus Ticket has been designed for distributors. It allows them to sell a wide range of tickets by integrating just a single API.
Korus Ticket offers a unified ticketing system. Under the hood, the Korus Ticket is actually an aggregation of ticketing
systems with a robust cache system organized around a set of entities.

Korus Ticket big picture
## Descriptions of Korus Ticket unified model's objects

### TicketIssuer

A ticket issuer is an entity responsible for managing and issuing tickets for an event, transport or any other service
requiring a reservation.

### Catalog

A Catalog is the ticket issuer's collection of [products](#product) and [events](#event). There is usually only one Catalog per TicketIssuer.

### Product

Products are elements that can be purchased to access an Event. The price and availability of a product at specific
date and for a specific category are specified in the [Offer](#offers) object.

### Event

Event is an activity that can occur one or multiple times. Every occurrence of this event is a [Session](#session).

### Offers

It is the price table of a product. Offers defines the price and availability of a [Product](#product) at a specific
date.

### OfferTicket

The tickets contained in an [Offer](#offers). A tickets give access to an Event's sessions.

### Session

Session is an occurrence of an event.

### Reservation

A reservation temporarily holds an [Offer](#offers), guaranteeing its availability and price for a limited time in the ticket
issuer's system.

### ReservationItem

The content of a [reservation](#reservation). Typically, items are the [offers](#offers) being reserved.

### Order

An Order is an actual booking in the [ticket issuer's](#ticketissuer) system.

### OrderItem

The content booked. It contains the detailed price and the booked tickets.

### OrderDocument

The files associated to the [Order](#order). These are typically the customer's tickets for the [Event](#event).