I'm not sure I understand the question... but I'll give it a crack.
Molle is the tac gear that has webbing that accepts gear fairly easily. It's all connected by straps... where as Alice gear used Alice or Malice clips to hold everything in place more or less. I am pretty sure you can put almost anything ALICE on a Molle too if desired.
Molle means it's configurable... that you take a base ( the vest or PC ) and can put what you want on it, gives options to pick and choose what you carry for the mission you are going to do. You can configure sever different load-outs for the same base if wanted. ( like if you decide to use pistols only in Sogo... you could set it up for a pistol load out. Next week, your going to play a field game, so you re-do it and put your rifle pouches on it... ect. ) You can arrange it how you like, and works best for you.
Most Tac vest ... if they aren't Molle ( configurable pouches more or less ) have fixed mag pouches, and utility pouches on them.
A full vest and some Plate Carriers ( PCs) cover the entire torso of an operator. Most these full cover options, when loaded ( full of mags, and gear) can weight a hefty amount... and in my opinion, limit mobility. I had found it hard to squat down, or even just bend over while staying low a bit difficult at times wearing, especially when loaded. ( Mags don't "bend" when you do. ) It generally forces you to keep your torso straighter , having to rely on bending at the knees more than bending at the waist. Doing that, sometimes you can't duck or get down quick enough to save you when someone pops shots at you.. or simply can't get down low enough. ( like behind a low wall, or structure, and still remain in a up-right, non prone position.)
In real life , real battle situations... you'd probably want to loose mobility, for the extra protection... but in airsoft I personally feel mobility is far better than heavy protection.
Tac vest... are just that. Tactical Vest. It is put on, and worn like a vest. Some real tac vest are lined with bullet proof material, or rated to stop bullets by kevlar and other absorbing impact systems.
Airsoft vest are modeled after these... usually with all the pouches you'd generally need for the job they are designed for. ( usually Urban Assault , like SWAT team, or Urban CQB environments. )
A PC .. is worn somewhat like a vest, but it straps or buckles on , and uses actual plates for extra heavy armor protection. Some have some other impact absorbing weaves built in on top of using plates.
A real PC plates are 7 pounds each for the lightest rating plates... and go up from there.
pretty good at stopping bullet shots that would normally injure you or kill you... but ... they aren't 100% protection either.
Most PCs are designed to be load bearing... which means weight is generally displaced across the stronger parts of your body, so the weight doesn't seem as heavy when carrying gear. ( Like your waist and shoulders.)
( Just like a Kevlar helmet PSGT issued by Army Infantry to it's foot soldiers... will stop a 50 cal bullet in a direct hit... saving a hole in your head... but it will not stop the force of the bullet from breaking your neck on impact. It's situational in both the PCs and Helmet... giving you a 50% better chance to survive... depending on what exactly and how exactly it happened. Very situational. )
Airsoft PCs are much lighter ( unless you are hardcore and use an actual Eagle PC system. ) thank goodness. Now they come out with the RAVs and Modular FOX , and MOPC systems for airsoft... it's a bit easier to have a realistic looking system, but much more comfortable and mobile base to use.
Unlike a "chest rig" ... both the VEST and PCs offer back options, where it's easier to have water carriers , and extra gear for your load outs. Chest rigs are generally juts designed for carrying all the ammo you need for a mission and mags in most cases, any extras like water, ect... have to be provided another way... or extra stuff you'd wear like a back pack are needed for extended duty/assault.
Alright, there's ya another chapter in Dragonpedia to read, lol!
