Agent classes are what makes Valorant have slight similarities to the MOBA's like League of Legends and Dota 2, and are a vital element of the game.
It is no secret that winning in Valorant is a team effort and not something that a person can do on its own. As the game has agents with different styles, skills and weapons, having the perfect team composition is crucial.
FPS Game Based on Roles
Before Valorant most FPS games had that were mostly based on the weapon type and the in game responsibilities, rather than separate Agents with Abilities. For everyone that strives to be good at Valorant, having good knowledge of the roles, and what they do is crucial. Valorant Agents are separated into four roles, and each of them have their own set of abilities for different playstyles.
The good thing about Valorant is that there are set Roles, in a team environment this is so important.— Liquid ScreaM MA (@ScreaM_) April 12, 2021
I had so much struggle in CS with that because people wanna get the best positions, im glad im not dealing with that problem anymore
Duelists are the offensive experts who excel at making aggressive and self-sufficient scenarios to engage the opponents. Their abilities help them be the Entry Fraggers and perform the High-Risk & High-Reward actions to gain massive advantage on the field.
As Valorant is a team game, and every player has a role, Duelists love being enabled by the other three, and depend on them to lower the risk in the engagements. What is expected from a Duelist is to have high KDA and Damage, and be the STARS of the game. Given their role, it is not recommended to have more than 1 Duelist in a team composition, as it would be a massive overkill.
Supports and In-game leaders is what describes the Sentinel role the best. Given their passive play style and abilities that make them be in the last line of fire, Sentinels are the perfect example of In-game leaders, and it is usually expected from them to dish out a round winning strategy and clutch calls during the game.
They have a variety of tasks in the game as Cypher and Chamber are the information gatherers, Killjoy is the defensive expert and Sage is the ultimate Support as she can close and slow down entry points and heal her allies. It is important to know, that when playing a Sentinel your KDA won't be perfect as it is not expected from you to dish out high frags.
The Initiators can do two things: crowd control and reconnaissance. In the bigger picture, their role is similar to the Sentinels, but more focused on gathering intel and helping the duelists with the initial pushes. Skye and Sova have abilities that help them gather info of the enemies position, and KAY/0 and Breach are focused more on the crowd control part.
The newest addition to the game, Fade, looks like a Skye-Sova hybrid, and she will probably take the role of a lurking-reconnaissance agent. Initiators are important, and can take on many roles, from the defensive role of a Sentinel or Controller, to a proactive one of a Duelist. It isn't uncommon to see a high KDA Initiator carrying a game, so if you feel like taking multiple roles on yourself, Initiator is a good path to take.
Controllers as the name suggests are experts at controlling the playground as their smoke abilities disrupt the enemy sight lines. As the main goal in Valorant is focused around the sites and planting the spike, vision and contested ground is a key factor of winning a round.
By using smokes, enemies positions are vulnerable, and by disrupting it, Controllers decrease the chances an enemy has to engage your team from a more favorable spot. Omen is more of a lurking Controller and differs from the other three, as he has abilities to flank the opponent and smoke spots other agents cannot. Viper, Brimstone and Astra are masters at controlling the battlefield as their smokes can enable the duelists to enter the site at ease and establish the needed positions before the engagement.