Difference between the trait and phenotype

There is little difference between the words phenotype and trait. 
DNA is made up so chromosomes of which there are 23 pairs. Each of these pairs contain alleles; segments of DNA that code for a trait, such as eye colour. Each allele codes for this trait individually however only the dominant allele is expressed. For example one might have an allele for blue eyes and an allele for brown eyes but the allele expressed, the dominant one, is the allele for blue eyes and hence the individual appears blue-eyed. The phenotype is the expressed trait (in the case the individual's blue eyes are the phenotype).Thus an individual contains two alleles for one trait; the expressed allele is the phenotype. 

However it should be noted that the word trait can be used in a such a way so as to express an individual characteristics that are unrelated to biology. In other words one's mannerisms may also be described as one's traits.