Genetic recombination is transmission genetic process where combination of alleles at different loci in 2 different parental become one offspring .

recombination is chromosomal crossing over .
Genetic recombination is the transmission-genetic process by which the combinations of alleles observed at different loci in two parental individuals become shuffled in offspring individuals.

In molecular biology, recombination generally refers to the molecular process by which genetic variation found associated at two different places in a continuous piece of DNA becomes disassociated (shuffled).

In this process one or both of the genetic variants are replaced by different variants found at the same two places in a second DNA molecule.

One mechanism leading to such molecular recombination is chromosomal crossing over.