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Glossary
Sleep terms, explained
Short, plain definitions of the words you'll see on product pages and spec sheets. Each one links to a guide when there's more to know.
C
- CertiPUR-US
- A certification program for polyurethane foam content, emissions and durability.
H
- Hybrid mattress
- A mattress with a coil support core and foam or latex comfort layers. Read the guide →
L
- Loft
- The height of a pillow when lying flat. Read the guide →
M
- Memory foam
- Viscoelastic foam that softens and contours with heat and pressure. Read the guide →
P
- Percale
- A plain cotton weave that feels crisp and breathes well. Read the guide →
- Pocketed coils
- Individually wrapped springs that move independently for support and motion isolation.
- Prorated warranty
- Warranty coverage where you pay a growing share of replacement cost as the mattress ages. Read the guide →
S
- Sleep trial
- A period during which you can return a mattress, often after a minimum break-in time. Read the guide →