Yes, it is what get your signal from the radio to the antenna, but what is your question.
If you are asking about length, then not really. Long enough to get where you need with some slack, not too long that you have a lot coiled up someplace. There is no "magic" length however.
Type, yes. CB antenna's or mounts generally come with the correct 50 ohm type cable. RG-58, RG-8X are what you need. RG-59 is 75 ohm and will cause problems.
Condition is important too. No cuts or splices. No sharp bends, just gentle curves. If its folded over too tight it will damage the inside insulation and coule cause a short.