This is because the Earth's axis is tilted 23.45&#176; to the ecliptic, the plane of the Earth's orbit around the sun.
(This; is; because the Earth's axis is tilted 23.45&#176; to the ecliptic) (the Earth's axis; is tilted; 23.45&#176)
This the Earth's axis
is is tilted
because the Earth's axis is tilted 23.45&#176 to the ecliptic
23.45&#176