A Nintendo DS. Source: vividgamer.com
There are two tools that are key to the interaction between players of Pokémon: the computer, and the Nintendo DS. Because Pokémon is platform specific, in order to actually do any battling or trading, a player must connect their Nintendo DS to the internet wirelessly. However, in order to set up these interactions, a player needs to first contact another via community websites, which is why a computer is also necessary.
Using these methods, players can set up battles among friends, rivals, or even complete strangers in order to test the strength of their team. Because they can convene online, they can also form friendships, teams, alliances, and even set up tournaments. Setting up trades are a little more tricky, because most players look for specific Pokémon when attempting to trade, or even specific attributes on a specific Pokémon (Here is a link to an example of a Trade fourm, where a trader advertises what pokemon they have for trade). They may also set up trade chains so that every person involved in the chain will eventually get the Pokémon that they wanted.
Here’s an example of a Pokémon battle from an international tournament:
[youtube]http://www.youtube.com/watch?v=HptcKIEANks[/youtube]
These community websites are also very useful for the sharing of information. The message boards are especially helpful, because the Pokémon that are popular in the battle scene are the ones that are most discussed. In this sense, they treat Pokémon as an academic subject. They perform research and run battle scenarios in order to determine how well the Pokémon performs against others and from this they write up reports that are shared for review by the entire community.
This has led to the creation of websites like Smogon, where a database of competitive Pokémon move-sets and builds is compiled and continually updated based on the Pokémon commonly appearing in each tier. These databases are great for both the theoretical aspect as well as the actual battles, because players can then build the ideal Pokémon that they want to use.