Auto Insurance Deductible Notation

Hi,

I have a (newbie) question about Auto Insurance Comprehensive/Collision Deductible.
Have been shopping for Auto Insurance recently, and have noticed that Comprehensive/Collision Deductible are mentioned in two forms:

1. Dollar Amount like: $500 or $1000
2. Ratio like 1:500 or 1:1000

Have googl'ed around but was unable to find an answer.
Could someone tell if there is any difference between the two ?

Thank you..

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