substitúciu

Substitúciu is the act or process of replacing one element with another. The term originates from Latin substitūtio, through Old French and other Romance languages, and is used in many disciplines to denote a temporary or permanent stand-in, swap, or replacement.

In mathematics and computer science, substitution refers to replacing variables or expressions with other values. The substitution method solves systems of equations by substituting one variable with an expression in terms of another. In cryptography, a substitution cipher replaces each unit of plaintext with another unit according to a fixed rule, producing ciphertext.

In biology and chemistry, base substitutions occur when a nucleotide is replaced by a different nucleotide in DNA, which may alter the encoded protein. Amino acid substitutions arise when a nucleotide change leads to a different amino acid in a protein.

In economics, the substitution effect describes how consumers switch to substitutes when relative prices change, affecting demand. The concept also appears in linguistics, materials science, and other fields to denote a stand-in that preserves function or value across contexts.