Fire Retardancy
When we say the fabric is fire retardant, it means that it has the ability to withstand light heat source such as cigarette butts or light open flames from matches.
In general, the most basic Fire retardancy (FR) Standard is the American Standard NFPA 260 / CAL 117 or the British Standard BS5852 Source 0. Higher standards would be CRIB 5 or IMO Standards, which is generally not necessary for domestic use.
In the photo below, we can see how CRIB 5 testing is performed. Although the furniture is fire retardant, it does not necessarily mean it would be burn proof. Instead, it withstands the heat and does not let it spread as quickly as compared to ordinary fabric.