Key Difference: The axis is an imaginary line through both the north and south poles on which the Earth rotates. An orbit is a curved path that is taken by an object around a star, planet, moon, etc.

Oxford Dictionaries defines Axis as,

• An imaginary line about which a body rotates: The Earth revolves on its axis once every 24 hours. 
• In Geometry, an imaginary straight line passing through the centre of a symmetrical solid, about which a plane figure can be conceived as rotating to generate the solid. 
• An imaginary line which divides something into equal or roughly equal halves, especially in the direction of its greatest length.

The axis is an imaginary line through both north and south poles on which the Earth rotates. The earth spins on an axis, unlike a top or rolling ball, it does not spin perfectly horizontally or vertically. Instead, it spins at a 23.5 degree tilt. This tilt is also what is responsible for different climates and seasons at different times on the planet. Axis is commonly referred to in mathematics. An axis of symmetry is a line, which divides a two-dimensional object into identical shapes. An axis may also be referred to in science, in technology, in music, in industry, in geography, etc.

An orbit is a curved path that is taken by an object around a star, planet, moon, etc. Thus, we can simply define it "as the path determining the motion of a body around the other body". The most common example is our solar system in which planets like Earth, Saturn and Jupiter follow an orbit around the sun.

There are two types of Orbits: Geosynchronous Orbit and Geostationary Orbit. A geosynchronous orbit is an orbit around a planet which has the same orbital period as the planet’s rotation period. Whereas, geostationary orbit is a kind of geosynchronous orbit but with an addition feature. It remains stationary with respect to a single point on the surface of the planet.

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