This is the exact current Central Time, live. In winter it shows CST (Central Standard Time, UTC−6); from spring to fall it automatically switches to CDT (Central Daylight Time, UTC−5). It follows the America/Chicago zone, so daylight saving changes are handled for you — no need to add or subtract an hour yourself.
CST vs CDT — what you're seeing
"Central Time" is the umbrella term; CST is the standard-time half of the year and CDT is the daylight-saving half. The clock above shows whichever is currently in effect. To turn a Central time into another zone, use the time zone converter; to compare it with other US zones at a glance, see US time zones.
Where Central Time is used
Central Time covers a broad swath of North America — much of the central United States (including Chicago, Dallas, Houston, San Antonio, Minneapolis, Kansas City, New Orleans and Memphis), a large part of Mexico, and central Canadian provinces such as Manitoba. Most of these observe daylight saving, though some regions do not.