Our basic understanding of the Sun is currently being transformed. This general review summarises the basic properties of the Sun and mentions some of the key recent discoveries on fundamental topics which have many implications for plasma processes elsewhere in the universe. It raises major puzzles that have not yet been answered such as:
How is the magnetic field generated?
How is the corona heated?
How do solar flares occur?
How is the solar wind accelerated?
In each case, the questions have multiple parts, some of which have been recently answered with the help of spectacular space observations, while others are being refined in ways that will be described. If particular importance is the way the solar atmosphere interacts in subtle and complex ways with the magnetic field.