Sync speed
From The Glossary of Digital Photography
The shutter speed a camera uses when connected or 'synced' to an electronic flash. Typically the sync speed refers to the maximum speed that can be used. Older SLR film cameras with focal plane shutters were often limited to 1/60th of a second. Modern digital SLR cameras typically have sync speeds of 1/90 to 1/125 of a second. Sometimes the maximum sync speed is dependent upon which flash unit is used.
