These are some of the common types of roles that exist in Fleet PvP. This does not assume every possible role in the game but instead focuses on the most basic roles. Below are brief overviews of each of the roles. If you want more specifics, check out each role and the guides that they contain.
The purpose of a Tacklers is to keep the enemy ships from warping away/moving around. This is accomplished by the use of Warp Scramblers/Disruptors and Stasis Webifiers. In some situations Warp Disruption Bubbles can be used, and even Interdictor Bubbles.
The purpose of direct damage ships is to destroy the enemy ships as fast as possible. Most of the time this means Battleships, Battlecruisers or HACs. There are also a couple philosophies ships in this role can have:
Support ships concentrate mostly on suppressing enemy fleet capabilities with Electronic Warfare, and sometimes enhancing friendly ships. Support are mostly composed of Combat Recon Cruisers, Force Recon Cruiser, Electronic Attack, and Logistics making them great counters for other support fleets while helping their own fleet.
Reconnaissance scout out ahead of the fleet to find enemies or to avoid them. While any ship can fit a Cloaking Device, there are only certain ship types that are specifically tooled for covert cloaking and can therefore fit the vastly improved Covert Ops Cloaking Device II: Covert Ops, Stealth Bombers, Force Recons.
Ships that fit modules that give a bonus to the entire fleet are Command Ships.
Large fleets will often have a dedicated section that protects the large fleet from interference. This is called the anti-support fleet.
Can be quite disruptive in red ratting systems.