The difference between Activate and Trigger

Activate as a verb (transitive):

To encourage development or induce increased activity; to stimulate.

Activate as a verb (transitive):

To put a device, mechanism (alarm etc.) or system into action or motion; to trigger, to actuate, to set off, to enable.

Activate as a verb (transitive, chemistry, physics):

To render more reactive; excite.

Activate as a verb (transitive, biology):

To render a molecule reactive, active, or effective in performing its function.

Activate as a verb (transitive, physics):

To render a substance radioactive.

Activate as a verb (transitive, chemistry):

To hasten a chemical reaction, especially by heating.

Activate as a verb (transitive, computing, software):

To remove the limitations of demoware by providing a license; to unlock.

Activate as a verb (transitive):

To aerate in order to aid decomposition of organic matter.

Activate as a verb (transitive, military):

To organize or create a military unit or station.

Activate as a verb (transitive, sports):

To bring a player back after an injury.

Trigger as a noun:

A finger-operated lever used to fire a gun.

Trigger as a noun:

A similar device used to activate any mechanism.

Trigger as a noun:

An event that initiates others, or incites a response.

Trigger as a noun:

A concept or image that upsets somebody.

Trigger as a noun (psychology):

An event, experience or other stimulus that initiates a traumatic memory or action in a person.

Trigger as a noun (music):

An electronic transducer allowing a drum, cymbal, etc. to control an electronic drum unit or similar device.

Trigger as a noun (music):

A device that manually lengthens (or sometimes shortens) the slide or tubing of a brass instrument, allowing the pitch range to be altered while playing.

Trigger as a noun (electronics):

A pulse in an electronic circuit that initiates some component.

Trigger as a noun (databases):

An SQL procedure that may be initiated when a record is inserted, updated or deleted; typically used to maintain referential integrity.

Trigger as a noun (online gaming):

A text string that, when received by a player, will cause the player to execute a certain command.

Trigger as a noun (archaic):

A catch to hold the wheel of a carriage on a declivity.

Trigger as a verb (transitive):

To fire a weapon.

Trigger as a verb (transitive):

To initiate something.

Trigger as a verb (transitive, sensitive):

To spark a response, especially a negative emotional response, in (someone).

Trigger as a verb (intransitive, especially, electronics):

To activate; to become active.