It is common for some learners to think that the seasons are due to how the Earth moves closer and further from the Sun as it orbits. The Earth's orbit is not perfectly circular, but rather an ellipse, so the Earth-Sun distance does change during the orbit. However if Summer occurred when nearest (and Winter when furthest from) the Sun then the North and Southern hemispheres would experience the same seasons.
Perihelion (closest approach) occurs in early January and aphelion (furthest point) in July each year, but the tilt of the Earth on its axis (relative to the plane of its orbit, the ecliptic*) has more effect on the seasons.
Read about the nature of alternative conceptions
Read about some examples of science misconceptions
Read about historical scientific conceptions
* We usually think of the Earth's axis as being tilted, but there is no absolute 'up' in space (aliens approaching Earth would have no reason on to put the Northern hemisphere at the top of any charts they might make), so we could just as well think of the Earth as being vertical (and the ecliptic as being tiled by comparison) or even horizontal – and indeed William Gilbert used this convention in his book on the Magnet. However, if we take the Sun as our focus and imagine the Earth orbiting the Sun horizontally (that is, take the ecliptic as horizontal) then the Earth's spin axis is titled by comparison.
