By contemporary, we mean mundane as well as modern. Contemporary campaigns are those set in the real world during a time period close to the modern day - the twentieth century or early twenty-first.
The standard character generation rules work well for any point in this period, though there's a few skills which would be rare or non-existent during the early twentieth century. The High Tech supplement covers equipment during this whole period, which on the YAGS TL scale equates to TL 6 (1900 - 1945), TL 7 (1945 - 1980) and TL 8 (1980 - 2020).
Campaigns set during the present day are as greatly varied as any other setting. They have the advantage of drawing upon huge amounts of free and extensive sources of information, plus the the feature that most players will be familiar with the setting. Of course, it's possible for a contemporary setting to be as alien to players as a historical or fantasy one is - not many players will have first hand experience of Africa for instance.