Updated

If you've ever had work done on your house, you've probably heard contractors spout a few terms that have you scratching your head. For instance, what exactly is "R&R" -- an afternoon siesta? And for that matter, what exactly are you doing to your home -- a renovation, restoration, or remodel?

Allow this installment of Learning the Lingo to clear up these mysteries and more.

For starters: A renovation is making something that's old new and improved (i.e., updating your master bathroom with new tile and fixtures). A restoration is returning something to its original state (like pulling up the carpet and sanding and polishing the hardwood floor). And a remodel is giving something a whole new purpose (converting a coat closet into a powder room).

Got it? Now here are some other terms contractors throw around. Understand them, and help get your redos done without a hitch.

R&R

If you think this refers to the relaxation and recreation you'll enjoy once your renovation is complete, think again. "R&R" is the term contractors frequently use (and that you may see on their invoice) to mean " remove and replace." It describes a simple renovation project that involves removing and replacing cabinetry, fixtures, and/or appliances without structural or mechanical changes (the latter of which is something you might do to a kitchen or bathroom).

-- -- --

Load-bearing wall

There are walls that simply divide rooms called non-load-bearing walls, and you can pretty much knock them down or relocate them at your discretion (hello, open floor plan!). Then there are load-bearing walls that you won't want to touch at all, because they support the weight of the floors above. Knock one of these babies down, and a portion of your whole home could come down with it.

So how can you tell which is which? Generally, load-bearing walls are stacked directly on top of one another Another clear sign: Check your basement for beams, which indicate where load-bearing walls are resting. When in doubt, consult a contractor; this is not something to leave to guesswork. At all. Got that?

-- -- --

Drywall

Also known as plaster board, gypsum board, and wall board, this is the flat surface of most interior walls -- to which you apply paint, wallpaper, or tile. When selecting drywall, it's a good idea to see that it contains additives that reduce mildew, increase fire resistance, and lower water absorption -- all features that merit the minor extra expense. Drywall sheets are securely fastened to the studs (see below).

-- -- --

Studs

No, we're not talking about Channing Tatum (at the moment, anyway). We mean the basic wood frames hiding behind your walls that keep your house from collapsing into a flimsy and expensive pile of drywall. And while you rarely see studs (still not talking about Channing), it's good to know where they're hiding behind your walls since that's where you'll want to hammer nails and hang heavy pictures, shelves, or flat-screen TVs. A nifty device called a stud finder can hep you locate studs by detecting the metal nails that hold them together.

-- -- --

Rebar

Short for "reinforcing bar," "rebar" refers to those ribbed steel rods placed in concrete foundations and retaining walls that give the structure extra support. If you're adding an extra room to your home, you'll need foundation (poured concrete), then add rebar -- sort of like adding drinking straws into a milkshake that then hardens around them.

-- -- --

HVAC

This may sound like a team of guys in gloves, gas masks, and one-piece yellow jumpsuits, but "HVAC" is actually much simpler and infinitely more benign: It stands for "heating, ventilating, and air conditioning." Regular maintenance of your HVAC system is a must and can substantially add to the value of your home (keep your receipts). Many a deal has fallen through at the last minute because the inspection found that the HVAC system hadn't been maintained and needed to be replaced.

-- -- --

Retrofit

This involves the addition of new technology or features to older systems. Retrofitting is becoming more and more popular as people attempt to make their homes greener and more energy-efficient. A retrofitting project could be as simple as replacing the windows in your home with the double-pane variety, or as complex as replacing all the old plumbing with new copper pipes.

-- -- --

Fuse box

In the movies, this is what the scary hooded guy uses to cut off the electricity before he does his dirty work inside the house. Also called a circuit breaker box, it's generally a small metal cupboard with a lot of switches that control and distribute energy to specified parts of your home. Each room of your home generally has its own toggle switch, and if the previous owners or builders were kind, they've labeled them. The beauty of that is apparent if you (or a contractor) do any electrical work on your home: You can easily turn off the correct power switches before starting the work -- or join one of the 400 people per year who end up electrocuted in this manner (don't say we didn't warn you).

-- -- -- -- --

More from realtor.com: Which House Should You Buy?