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In physics, motion is a change in position of an object with respect to time. Change in action is the result of an unbalanced force. Motion is typically described in terms of velocity, acceleration, displacement and time . An object's velocity cannot change unless it is acted upon by a force, as described by Newton's first law. An object's momentum is directly related to the object's mass and velocity, and the total momentum of all objects in a closed system (one not affected by external forces) does not change with time, as described by the law of conservation of momentum.

A body which does not move is said to be at rest, motionless, immobile, stationary, or to have constant (time-invariant) position.

Motion is always observed and measured relative to a frame of reference. As there is no absolute frame of reference, absolute motion cannot be determined; this is emphasised by the term relative motion. A body which is motionless relative to a given reference frame, is still moving relative to infinitely many other frames. Thus, everything in the universe is moving.

More generally, the term motion signifies any temporal change in a physical system. For example, one can talk about motion of a wave or a quantum particle (or any other field) where the concept location does not apply.

In physics, velocity is speed in a given direction. Speed describes only how fast an object is moving, whereas velocity gives both the speed and direction of the object's motion. To have a constant velocity, an object must have a constant speed and motion in a constant direction. Constant direction, typically constrains the object to motion in a straight path. A car moving at a constant 20 kilometers per hour in a circular path does not have a constant velocity. The rate of change in velocity is acceleration. Velocity is a vector physical quantity; both magnitude and direction are required to define it. The scalar absolute value (magnitude) of velocity is speed, a quantity that is measured in metres per second (m/s or ms⁻¹) when using the SI (metric) system.

For example, "5 metres per second" is a scalar and not a vector, whereas "5 metres per second east" is a vector. The average velocity v of an object moving through a displacement during a time interval (Δt) is described by the formula:

The rate of change of velocity is acceleration – how an object's speed or direction of travel changes over time, and how it is changing at a particular point in time.

Gare do Oriente (Portuguese pronunciation: [ɡaɾ(ɨ) du oɾiˈẽt(ɨ)]) or Lisbon Orient Station is one of the main transport hubs in Lisbon, Portugal. It was designed by the Spanish architect Santiago Calatrava and built by Necso. It was finished in 1998 for the Expo '98 world's fair in Parque das Nações, where it is located.

It encompasses a Lisbon Metro station, a high-speed, commuter and regional train hub, a local, national and international bus station, a shopping centre and a police station.

The station bears considerable resemblance to Calatrava's earlier Allen Lambert Galleria within Toronto's Brookfield Place. Some influence from Gothic architecture can also be found.

Oriente Station is one of the world's largest stations, with 75 million passengers per year which makes it as busy as Grand Central Terminal in New York.