The 'Ether' part of Ethernet denotes that the system is not
meant to be restricted for use on only one medium type, copper
cables, fibre cables and even radio waves can be used.
Fast Ethernet Network was developed as an upgrade to traditional
Ethernet Networking. Fast Ethernet improved traditional Ethernet by
increasing transfer rates 10 times, from 10 Megabit to 100 Megabit
speed.
Gigabit Ethernet Network is an upgrade on Fast Ethernet Network
equivalent to Fast Ethernet Networks improvement over Fast Ethernet
Network, offering speeds of 1000 Megabits (1 Gigabit)
Cisco have a good document with diagrams and a reasonable amount
of depth that answers your questions on 10/100/1000 Ethernet. See
related link.
Ethernet card would be 10Mbps (mega bauds per second) Fast
Ethernet card would be 100Mbps. Most ethernet cards sold today are
Fast Ethernet or better. Look for the 100Mbps or the 10/100Mbps
specification. The only difference between the both is the
speed.
Hence both cards are basically the same using the same
technology except the fast Ethernet card can run on 10/100mb/s, an
astonishing speed.
Original 10Base2, 10Base5 and 10baseT Ethernet (thin coaxial
cable, thick coaxial cable and twisted pair, respectively)
specifications offered a 10Mbit/second throughput (data transfer
rate). Although 1 Byte is 8 bits, 10Mbits in practice doesn't mean
1.25MBytes/second, because there's some extra information
transferred. On average it can be seen as a ~1MByte/second link
speed.
Then new standards appeared, some of them exotic (like 100VG
AnyLan), but the new Ethernet standard was 100baseTX, which used
twisted pair (like 10baseT, but with slightly higher quality
requirements - Category 5 cable). It has been called Fast Ethernet,
as it offered 100Mbit/sec transfer speed, a 10-fold improvement.
Usually all the network equipment can talk both 10baseT and
100baseTX (for example network switches have "10/100" ports).
But this was not enough - then came a next speed-up: the
1000baseTX, still running on twisted pair, but with even higher
cable quality requirements, offering 1000Mbit/s transfer speed,
thus called Gigabit Ethernet: 1000 Mega = 1 Giga.