The strings
The bass guitar strings come in many gauges and string styles, including round-wound, flat and primed wounds. Strings are sold individually or in packages with corresponding gauges ranging from extra light, light, medium and heavy.
Round spring type
Round-wound type strands have a center core strand with an outer round thread that wraps tightly around the strand. This type of string gives a bright sound and creates a good durability.
Platformed type
Platformed type of strings have a center core strand with an outer flat strand that encloses the strand tightly. This type of string feels smooth against the fingers and produces a muddy sound that is close to an intermediate frequency level without interruption.
Ground-wound Type
The type of strands that have a wound wrap has a center core strand with an outer round strand that encloses the strand tightly. Grounding the outer thread to mimic the flat wound gives it a feel and sound that extends between the fuzzy sound of the flat wound strands and the gentle sound of those around the wound strands.
Coated strings
Coated strings last longer because you can easily wipe them off after each gig; Doing so removes grease and dead skin that rubs away from the fingers. Some bass string manufacturers now make colored strings that add to the look of your bass. The type of bass strings you buy for your bass guitar is ultimately your choice, but you get the best strings if you first consider your preferred string design and gauges, as well as how you ‘attack’ the strings when playing.
Source:danspela.com