A chromosome is a string of genes whose values are alleles (bits, tokens).  Two types of chromosomes are possible:  binary (continuous) chromosomes and enumerated chromosomes.  A chromosome is a part of an individual:  each individual in the population may be composed of one or several binary and/or enumerated chromosomes.  The contents of all the chromosomes in the individual determines its fitness.  The main task of the genetic algorithm is to create individuals with the highest fitness value, i.e., with the best genetics.

Chromosomes carry the values of variables (the genetic traits) which impact upon solving the problem.  When referring to continuous chromosomes, a chromosome is a single variable from a set of variables which impact on the solution of a problem.  When referring to enumerated chromosomes, a chromosome is a set of variables which impacts on the solution of a problem.  When using the GeneHunter Excel interface, the adjustable cells represent individual chromosomes for the continuous type.  For the enumerated type, all of the adjustable cells compose a single chromosome.