PCMCIA and PC CARD are normally interchangeable terms.
There are, however, 2 PC Card standards, the older one is PCMCIA, a 16-bit slot at 5 volts which is virtually equivalent to an ISA slot. The newer standard is called CardBus, a 32-bit slot at 3.3 volts, equivalent to a PCI slot in many ways.
Interesting stuff include SCSI cards for external CDROMs and hard drives, USB, Firewire, the usual LAN/Modem, Bluetooth adapters, adapters to link to cell phones for Internet/network connections, CompactFlash/SmartMedia...sound cards....there even used to be PCMCIA hard drives.