We put together a short overview for you that should help you to get a clear idea of the four bridge officers' roles:
Captain
The captain oversees the status of the ship and gives orders to each of their officers. He or she is also able to take over each role position to perform actions personally.
Engineer
The engineer controls the energy flow of the ship. They can direct energy to specific systems and manage repairs of the ship.
Helm
The helm controls the ship itself. They fly the ship and are also responsible for Impulse and Warp travels.
Tactical
The tactical officer is responsible for weapons, shields and targeting. They fire the ship's weapons (Phasers or Photon Torpedos) at enemies and raise or lower the shields.
Distributed Systems
A few systems are shared between the Engineer, Helm and Tactical: the Teleporter and the System Disruption. All Stations are able to control these systems but only one station at a time can open the panel.
Captain
The captain oversees the status of the ship and gives orders to each of their officers. He or she is also able to take over each role position to perform actions personally.
Engineer
The engineer controls the energy flow of the ship. They can direct energy to specific systems and manage repairs of the ship.
Helm
The helm controls the ship itself. They fly the ship and are also responsible for Impulse and Warp travels.
Tactical
The tactical officer is responsible for weapons, shields and targeting. They fire the ship's weapons (Phasers or Photon Torpedos) at enemies and raise or lower the shields.
Distributed Systems
A few systems are shared between the Engineer, Helm and Tactical: the Teleporter and the System Disruption. All Stations are able to control these systems but only one station at a time can open the panel.