Fold

Fold[f, x, list] gives the last element of FoldList[f, x, list].

Fold[f, list] is equivalent to Fold[f, First[list], Rest[list]].

Examples

Sum a list using Fold:

Fold[Plus, 0, {1, 2, 3, 4}]
(* 10 *)

Build a nested expression:

Fold[f, x, {a, b, c}]
(* f[f[f[x, a], b], c] *)

Please visit the official Wolfram Language Reference for more details.