Because of convergence issues in the 802.1D STP algorithm, IEEE developed 802.1W. 802.1W, also called Rapid STP or RSTP, includes enhancements to speed up the convergence with STP. One of the main problems of using Cisco's STP enhancements—PortFast, UplinkFast, and BackboneFast—is that they're proprietary and function only on Cisco switches. In most instances, you can use RSTP instead of Cisco's proprietary STP enhancements and get the same or better performance from your STP process.
For trunk connections using ISL or 802.1Q between Cisco switches, Cisco has enhanced PVST+ to allow RSTP to function correctly. Cisco calls this enhancement RPVST+. You do not need to configure anything special on the switch to use RPVST+.
Just as ...