The difference between Visa and Visa Signature cards is the level of benefits provided with the card, with Visa Signature having greater benefits.
Core Visa benefits include roadside dispatch, car rental insurance, and emergency card replacement/cash disbursement. Visa Signature cards have additional benefits including a minimum $5,000 credit limit, extended warranty coverage, travel and emergency assistance, and access to the Luxury Hotel Collection benefits.
In addition, the card issuer can choose to add other Visa, Visa Signature, or Visa Infinite benefits.