Constraint

Constraint may refer to:
 * Constraint (computer-aided design), a demarcation of geometrical characteristics between two or more entities or solid modeling bodies
 * Constraint (mathematics), a condition of an optimization problem that the solution must satisfy
 * Constraint (mechanics), a relation between coordinates and momenta
 * Constraint (computational chemistry)
 * Constraint (information theory), the degree of statistical dependence between or among variables
 * Constraints (journal), a scientific journal
 * Constraint (database), a concept in relational database

Particular types of constraint

 * Biological constraints, factors which make populations resistant to evolutionary change
 * Carrier's constraint on lung function in long thin animals
 * Finite domain constraint, in mathematical solution-finding
 * Integrity constraints in databases
 * Check constraint
 * Foreign key constraint
 * Observational constraint in science, a constraint on a solution implied by previous observations
 * Specific types of mechanical constraints:
 * First class constraint and second class constraint in Hamiltonian mechanics
 * Primary constraint, secondary constraint, etc. in Hamiltonian mechanics
 * Holonomic constraints, also called integrable constraints, (depending on time and the coordinates but not on the momenta)
 * Nonholonomic constraints
 * Pfaffian constraint
 * Scleronomic constraint (not depending on time)
 * Rheonomic constraint (depending on time)