"Sodium" refers to the element sodium, "alkanes" generally describes a mixture of saturated hydrocarbons. The preceding numbers "C x-y" give the range of carbon chain lengths (here C13-C17) of the alkanes. "Sulfonates" are salts/esters of sulfonic acids (R-SO2-OH).
Sodium C13-C17 alkanes Sulfonates are a mixture of substances which are used in cosmetic preparations where they act as surfactants (washing-active substances).