rate = rate of change. (微分) Refers to speed, currencies, increases, decreases, etc. 60km per unit hour; RMB7 per unit dollar, etc The rate is always ONE number: 60%; 7.12; 25%; etc Ratios refer to the mixtures of more than one thing and have comparisons (正比): Water and whiskey 2:1 = 2 parts water one part whiskey (ratio of 2 to 1) The ratio is always at least TWO numbers: 2:1; 3:4; 1:5:6; etc

As to noun rate may refers to: 1.A magnitude or frequency relative to a time unit "they travelled at a rate of 55 miles per hour"; "the rate of change was faster than expected" 2.Amount of a charge or payment relative to some basis "a 10-minute phone call at that rate would cost $5" 3.The relative speed of progress or change "he works at a great rate" 4.A quantity or amount or measure considered as a proportion of another quantity or amount or measure "the literacy rate"; "the retention rate"; "the dropout rate" Us to verb 1.Assign a rank or rating to "The restaurant is rated highly in the food guide" 2.Be worthy of or have a certain rating "This bond rates highly" And Ratio may refers to: 1.The relative magnitudes of two quantities (usually expressed as a quotient) 2.The relation between things (or parts of things) with respect to their comparative quantity, magnitude, or degree cowboy...