You can scout the planets of other players and see their fleets and buildings (if scouting is successful).
For exploration, you must have Loki) on the planet.
Read more about Intelligence in this article
You can send your fleet to attack other players' planets. In case of a successful attack, the fleet will bring you back the player's resources that he is able to carry away (depends on the total cargo ships in the fleet).
Player buildings on a planet can only be destroyed if the attacking fleet has special types of ships for destroying planetary buildings (planetary bomber Valkyrie).
Read more about Attack in this article
Similar to Scouting, but it takes place not on the planet, but by counter scouting of the enemy fleet in space.
Read more about Counterintelligence in this article
Similar to the Attack, but it does not take place on the planet, but by a counter attack of the enemy fleet in space.
Read more about Counterattack in this article
You can move your fleets and ships between your planets. For example, in order to support your planet when it is attacked by other players.
Read more about Support in this article
Blockade is a separate siege attack mode that blocks the enemy planet.
Read more about Blockade in this article
A special type of attack on the enemy planet. The main goal of such an attack is the destruction of the infrastructure of the planet.
Read more about Bombardment in this article
You can capture free planets or the planets of other players, provided that you have destroyed all the player's defensive buildings on the planet using Attack with special ships for planetary destruction (planetary bomber Valkyrie).
Read more about the Occupation in this article