An astrology chart is set for the place and time of any event, usually a birth. The chart is like a freeze frame of a moment in time as the planets are captured in their orbit.
Aspects are the relationships between planets that are measured by their geometric relationship with each other in the circle we call the zodiac.
When we draw a chart, it reflects the heavens from our perspective on earth. This is called a Geocentric perspective. So we see the Sun in the sky in the same way that we see the Moon and Mercury, Venus, Mars, Jupiter and Saturn ( the other planets are so far distant that they cannot be seen without special equipment.) So it is correct to draw the Sun in the position it is when we look up and see it there.
The centre of the chart represents EARTH. From Earth we see the Sun, Moon and Planets. So we draw the Sun in a position as if it were orbiting the earth, which it certainly does appear to do. The earth in fact orbits the Sun, but from earth it looks like things are happening the other way round. We live on earth, so our perspective is a valid one and we use that to draw the chart and the planets' positions. The circle in which we draw the zodiac represents the earth's path around the Sun, called the Ecliptic'.
In the top circle of the diagram are the Inner planets - imagine they fit into the grey area of the bottom circle which shows the Outer planets. In the top circle, the bright yellow disc is the Sun , the Red one is Mercury the Blue is Venus then comes Earth which is a turquoise or cyan colour. Imagine if you transposed the earth and Sun so that the Earth was in the Centre, and the Sun where the Earth belongs then the Sun would appear to be orbiting the Earth along with all the other planets. This would be the Geo-Centric perspective.