Assemble, Active, Leave and Repackage:

The EVE database uses multiple tables to store items it two ways, packaged and assembled.

Packaged

Items that are all identical can be stacked and are put into the packaged items table. Packaged items only have 3 attributes: location, item type and quantity. So, there is not a database record for each unit of ammo in a stack of 2000 units. There is one record, saying where it is, what type of item it is and how many are in the stack.

Pretty much anything can exist as a packaged item to be stacked.

You can not make a ship active while it is packaged. It must be assembled first.

You can not sell anything on the market without it being packaged, it needs to be identical to every other item of the type so that the buyer can know what they are getting.

Assembled

When a ship is assembled, it is moved into the assembled ships database. This gives it additional attributes, like shield, armor and structure hit points, a cargo hold location that things can be put into, fitting slots that can have modules put into them.

While a ship is assembled, it can no longer be stacked, because it is no longer identical to every other ship of that type.

Modules must also be assembled to be fit to ships. Modules can be damaged, so they need to have the ability to be unique to store that damage amount. When you fit a module to a ship, if it was packaged, it is automatically assembled.

Not all items can be assembled, like ammo. They always exist as a stack, even if only a stack of 1.

Most assembled items can be repackaged, assuming they are not damaged.

Blueprints are an exception, once they are assembled, by building from them or researching them, they can not be repackaged. Since all items have to be repackaged to be sold on the market, this is why you will not find anything except unresearched blueprint originals on the market.

Naming Ships

From the ships hanger, you can name any ship. This will allow you to have multiple ships of the same type, and know which is which. You can have one fit for short range and one for long range, and give them names that you will understand.

Warning. Other players can see the ship’s name when scanning from space. Calling them “long” and “short” is probably not a great idea.

Make Activate and Leave Ship

You can only fly 1 ship at a time (per account). To change which ship is active, right click and select make active. The ship has to be assembled before it can be made active.

You can leave the current ship by selecting Leave Ship on your current ship. This puts you in your pod. This is a way of moving multiple ships from station to station. Move one, leave, go back in your pod, repeat.