The term Haplotype and Haplogroup are similar and not used in genetic genealogy and population genetics exactly as they have been more strictly defined in genetics, in general. So any definition here is subject to criticism depending on the group you follow.

Haplotype, in genetics, is a group of genes or (segments of DNA) that are inherited together and exist in a number of individuals. Most usually restricted to a single chromosome and usually in proximity to each other. Often thus it becomes a classification of base-pair values for an inheritable condition or likelihood to get a disease. In genetic genealogy, haplotype has been used to define the relevant result of testing for STRs on the yDNA chromosome (specifically, the non-recombining region that stays fairly stable from generation to generation; and usually the non-coding or inter-gene region where STR sequences and their changes can survive.)

So, for genetic genealogy purposes, associate haplotype with a yDNA STR testing result. The number of markers tested and in the result determines the refinement of the haplotype. There are over 400 known STR markers on the Y chromosome.