It is customary to classify the several components of an airport in three major catego- ries: airside facilities; landside facilities; and the terminal building, which serves as the interchange between the two' (see fig.
A terminal is made up of several gates where planes park and passengers wait to board. In large terminals, these gate areas may be divided into sections known as concourses, filled with dining, shopping and lounge options, as well as restrooms and other facilities.
More than one terminal is neccesary to cater to the traffic at the airport. If there was only one terminal imagine the extra expenditure a plane would have to incurr before it can land . A plane can only land if the previous passengers traffic has cleared or it has been sufficiently cleared.
An Airport Layout Plan (ALP) is a scaled, graphical presentation of the existing and future airport facilities, their location on the airport campus, and pertinent clearance and dimensional information.
King Fahd International Airport (DMM) — Dammam, Saudi Arabia. At 299.61 square miles (776 square kilometers), King Fahd International Airport is the largest airport in the world by total area.
An airport terminal is a part of the whole airport – you can think of them as mini airports within one large airport complex. Each terminal has all of the facilities needed to operate individually (customs and immigration, security, check-ins, runways, gates, baggage handling, etc.).
More than 40 percent of hub airports' revenues involved passenger-related activities, such as terminal concessions, parking, and ground transportation. For large hub airports specifically, another 40 percent, including landing fees and terminal rents, came from passenger airlines (Exhibit 1).
The airside is that portion of an airport between the boarding gates and the airspace. Major elements of the airside are runways, taxiways, and navigational systems.