What are all the different categories of weapons and what upgrades are available for them?

In Mass Effect 2, weapons fell into six categories:

• Assault Rifles
• Shotguns
• Sniper Rifles
• Submachine Guns
• Heavy Pistols
• Heavy Weapons

Are these types the same in Mass Effect 3? Are there new weapon types?

Also, upgrades in Mass Effect 2 are not weapon-specific modifications. Instead, the player obtains upgrades through research which apply across an entire weapon type. For example, an Assault Rifle Damage upgrade will boost the damage output of all assault rifles that the player owns, not just a specific model.

Does this research oriented system exist in ME3 or are they only weapon specific?

Solution 1:

The 5 basic weapon categories(Rifle, Sniper, Sub, Pistol, and Shotgun) are unchanged, but you get a lot more of each of them. You can now carry one of each of them provided you have enough carry capacity.

Heavy weapons are still around, but they are temporary pickups in certain missions.

They dropped the weapon research mechanism as it worked in ME2.

Now each weapon has two upgrade slots similar to ME1, but much more streamlined. You can also upgrade each weapon individually. I.E. Upgrade a Mantis I to a Mantis II to get slight stat bonuses. This can all be done from the Shuttle Bay on the Normandy.

Solution 2:

The weapon types are the same as they were in ME2, however you can freely choose which types to take on any given mission, and heavy weapons can only be picked up in the world. Switching to a different weapon will drop the heavy weapon at your feet.

There are some research bonuses available as intel found throughout the game, but they are very general (+5% weapon damage, +5% shield strength, etc). You can also upgrade a specific weapon, slightly improving its characteristic, in the Normandy's shuttle bay.