Genomes can be classified in two ways.
Query genomes can be classified relative to the reference genomes in a genome project. This method does not give a full taxonomic classification (i.e. it does not include all ranks), but rather answers the question, "How closely related is my query genome to the reference genomes I have already submitted to this particular project?"
Reference genomes can be taxonomically classified by submitting them to a project with an attached reference database. In this case a phylogeny is predicted for the genome along with probablilities (p-values) that it belongs to each rank in the taxonomy.
This section includes tutorials for each of these classification methods.