Wikipedia: Anneal

In Metallurgy and Materials science annealing refers to a heat treatment wherein the microstructure of a material is altered, causing changes in its properties such as strength and hardness. Typically, this results in softening of the metal through removal of crystal defects and the internal stresses which they cause. In the semiconductor industry, silicon wafers are annealed, so that dopant atoms (usually, boron, phosphorous, or arsenic) can be incoporated into substitutional positions in the crystal lattice, resulting in drastic changes in the electrical properties of the semiconducting material.
In biology (genetics) to anneal means for DNA or RNA to pair by hydrogen bonds to a complementary? sequence, forming a double-stranded polynucleotide. The term is often used to describe the binding of a [DNA probe]?, or the binding of a primer to a DNA strand during polymerase chain reaction.
In computer science, [simulated annealing]? is a technique for searching for a solution in a space otherwise too large for "ordinary" search methods to yield results. It is a probabilistic technique based on formulas from physics describing an annealing process. See the book [Numerical Recipes]? for a good treatment.