What is a monohybrid cross and what is a dihybrid cross?

Monohybrid - A genetic cross made to examine the distribution of one specific set of alleles in the resulting offspring
Example: tall peas x short peas or TT x tt

Dihybrid - Hybridization using two traits with two alleles each.
Example: tall peas with round seeds x short peas with wrinkled seeds or TTRR x ttrr