Technology

Technology (often referred to as Tech) are buildings that you build which allows you to place Weapons once they are built.

The different Techs
There are 5 tech buildings within vanilla forts, but much more in modded forts. Each one unlocks a set of weapons, except the Upgrade Center that unlocks the upgrade possibility.

The Workshop unlocks the Mortar and the Swarm Missiles.

The Armoury unlocks the Flak and the EMP Rocket.

The Upgrade Center unlocks the ability to Upgrade.

The Munitions Plant unlocks the 20mm Cannon and the Cannon.

The Factory unlocks the Firebeam and the Plasma Laser.

The Tech Tree
You can't start the game by placing a Factory for 2 reasons : 1) you don't have the resources, 2) Tech tree.

In order to place a Factory or a Munitions Plant, you need to have a completed Workshop or an Armoury. If they are EMPd, they won't count either, same if you are selling them.

The Upgrade Center doesn't give access to tech, unless playing modded forts.