Merge Two Sorted Strings Lexicographically

What does “Merging Two Sorted Strings Lexicographically” Mean?

Lexicographical means that something is organized according to alphabetical order.

Lower case letters are different from upper case letters and are therefore treated as different elements. All upper case letters come before lower case letters. Alphabetic sorting is as follows: $A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z, a, b, c, d, e, f, g, h, i, $$j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z$