One ordinary star is the Sun and a good starting point for learning about
stars is to start with our star the Sun (It is important that you never look
directly at the Sun as this can cause blindness).
The Sun was formed 4.5 giga years (giga = 1,000,000,000 or one billion) ago and will last around another 5 giga years.
Image of the surface of the Sun showing the massive amount
of activity that occurs all the time. Image taken by the Trace NASA project.
The surface of the Sun is constantly changing in the image above it is possible to see the uneven surface of the Sun as it bubbles forth into solar flares.