Every round, on your character's turn, you may take a Standard Action, a Move Action, and a Swift Action (In any order). You may take a Move Action or a Swift Action in place of a Standard Action, but not the other way around. You may also take a Swift Action in place of a Move Action, but not the other way around. Finally, you may sacrifice all three of these Actions to perform a single Full-Round Action on your turn.
Full-Round Action
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Standard Action
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Move Action
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Swift Action
Full-Round Action: A Full-Round Action consumes all of your effort during a given round, effectively replacing all other Actions on your turn. Some uses of Skills require a Full-Round Action to complete. Examples include bypassing a lock (Using the Mechanics Skill), searching an area for clues (Using the Perception Skill), and entering a Force Trance (Using the Use the Force Skill). A Full-Round Action can't span multiple rounds; for example, you cannot perform a Full-Round Action that replaces your Move Action and Swift Action in the first round and your Standard Action in the following round.
Standard Action: A Standard Action is usually the most important Action you'll take in a round, and it often consists of some sort of attack- swinging a Lightsaber, firing a blaster, throwing a punch, hurling a Grenade, and so on. You can perform one Standard Action on your turn.
Move Action: A Move Action represents physical movement. The most common Move Action is moving up to your speed score. Standing up from a Prone position, opening a door, and drawing a weapon are also Move Actions. You can perform one Move Action on your turn, or two if you give up your Standard Action.
Swift Action: Most Swift Actions enable you to perform your Standard Action. Examples include switching a weapon's mode and dropping a held item. You can perform one Swift Action on your turn, or two if you give up either your Standard Action or your Move Action, or three if you give up both your Standard Action and your Move Action.
Free Actions and Reactions
Some Actions take such a negligible amount of time that they can be performed in addition to other Actions or they can happen out of turn:
Free Action: Free Actions consume almost no time or effort, and you may take one or more Free Actions even when it isn't your turn. Examples include calling out to your friends for help and taunting a foe. The GM puts reasonable limits on what counts as a Free Action. Reciting the epic history of the Rodian hunter clans takes several minutes (Or more) and therefore isn't a Free Action. You can't take Free Actions when you're Flat-Footed.
Reaction: A Reaction is an instantaneous response to someone else's Action, and you can use a Reaction even if it is not your turn. Examples of Reactions include making a Perception check to notice a bounty hunter sneaking up behind you and instantly activating a Force Power to absorb damage from an incoming blaster bolt. You may only take a single Reaction to any one Action or effect. A Reaction is always resolved after the Action that triggered it, though some Reactions (Such as the Negate Energy Force Power, or the Block and Deflect Talents) can affect the outcomes of the Action that triggers a Reaction.