Edward Tuft, who both invented and coined the term sparkline, described them as "data-intense, design-simple, word-sized graphics". Sparklines are the perfect tool to present trends or variations in data “at a glance”. Unlike the charts commonly used in APEX, sparklines are very small in size, often presented alongside or within text. Also, sparklines rarely contain scale or axis data and single data points are rarely singled out. To put it another way, charts provide the detail whereas sparklines provide a snapshot.And for those of you who simply prefer pictures, here they are:
If you're interested in learning more go to http://www.enkitec.com/products/plugins/sparklines and click on help or demo on the right.