Linked from
The 15 pages that link to Mixture, each with the reason it gives.
Mole fractionNarrower topic: Mole fractions describe the composition of mixtures.
Mass fractionNarrower topic: A mixture’s total mass is commonly the denominator.
Volume fractionNarrower topic: Its total volume provides the reference for constituent fractions.
Binary fluidNarrower topic: A binary fluid is the fluid-state case with exactly two components.