# 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 [ProductBases](#productbase). There is usually only one Catalog per
TicketIssuer.

### ProductBase

ProductBase are the main elements of a catalog. They allow grouping related products. They contain options with values
that can be used to filter products.

### Product

A Product represents a unique version of a product base (e.g., a 3-day park entry in price_type adult).
The price and availability of a product at a specific date are specified in the [Offer](#offers) object.

### Offers

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

### OfferTicket

OfferTickets are contained in an [Offer](#offers).
OfferTicket might allow all-day access or only a limited session time.

### OfferTicketSession

OfferTicketSession represents the time slot of an [OfferTicket](#offerticket).

### 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 with the [Order](#order). These are typically the customer's tickets for the event.