A lot of your life happens on your sofa. It's the place you perch as you catch up with friends over a glass of wine. Where you nestle in to read the best-seller you've been dying to get your hands on. Where you fall asleep waiting for your teen to get home safely from that first date.

It's no wonder picking the sofa that's right for you can be so fun — and so difficult. Some folks agonize over this decision more than any other interior design choice. This guide will help you pick a perfect-for-you sofa.

But first, a primer in sofa-speak. Commit these must-know definitions to mind.

Backs

Loose cushion: The cushions are separate from the back of the sofa (but you can also have a semi-attached cushion). These create a more casual look. A plus is the cushions can be removed and cleaned. If you want a less formal sofa that's soft and comfy, this might be the right back for you.

Tight: The back is all upholstery, with no cushions. This style creates a cleaner, more formal look and leaves you lots of room to toss in accent pillows.

Pillow: The back is made up of several large, unattached pillows instead of a cushion. If you have young children, beware: The pillows may end up being used to make a fort on rainy days.

Channel: In this variation of the tight-back sofa, the back is made up of several panels.

Curved: Instead of the back and arms of the sofa being distinct pieces, in this style the back curves around to form a solid line with the arms.

Camelback: The silhouette of the back is in an arch shape.

Arms

Rolled: These arms curve out and often have sofa padding, making them ideal for napping. Rolled arms are common on more traditional sofas.

Square: Tailored and boxy, these arms are more contemporary.

Seats

Tight: This is a firmer, tailored seat that does not have loose cushions. Usually you find tight seats on settees or formal sofas.

Bench: A single-cushion or bench seat has a clean, crisp appearance. Single-cushion sofas can get squished-looking in the center if you opt for all-down cushions, giving the sofa a sloppy appearance. Instead, try down-wrapped foam or spring-down cushions.

Cushion: This popular pick features two or three loose cushions that are not attached to the base. T-shaped cushions are those that wrap around the arm of the sofa.

Legs

Exposed legs: Many sofas on the market now have exposed legs. Sofa legs come in modern, straight lines, or more traditional turned legs. For a romantic look, add castors.

Skirted: If you love a traditional look, you might want a sofa with a skirt. Be warned, though: Skirts show dirt. Shoe polish wears off on them, as do the body oils of pets who sleep against the sofa.

Mary Carol Garrity owns a home furnishings store, Nell Hill's. This column was adapted from her blog at www.nellhills.com.

3 things to consider when selecting a sofa

The fit: Your sofa needs to fit your body, not the other way around. If you are a petite person, your sofa should be smaller in scale. If you are larger, consider a larger piece. If your sofa needs to fit lots of body types, add pillows and an ottoman to make those with short legs more comfortable.

The right dimensions: Create harmony in your living space by picking a sofa that is in proportion to the other furnishings in your room. Many people used to seek out a new sofa because they were tired of the fabric on their old one. These days, people often want to replace a too-large sofa, the scale of which is out of whack with their space.

The right tone: Your sofa needs to match the level of formality of the room. For a more formal room, for example, select a tight-back sofa. For a casual space, try loose-back cushions.