[2] The virus particles have a distinct shape; each virion has an icosahedral head that contains the viral genome, and is attached to a flexible tail by a connector protein.

[2] The order encompasses a wide range of viruses, many containing genes of similar nucleotide sequence and function.

However, some tailed bacteriophage genomes can vary quite significantly in nucleotide sequence, even among the same genus.

[3] Upon encountering a host bacterium, the tail section of the virion binds to receptors on the cell surface and delivers the DNA into the cell by use of an injectisome-like mechanism (an injectisome is a nanomachine that evolved for the delivery of proteins by type III secretion).

Once this has occurred, the prohead undergoes maturation by cleavage of capsid subunits to form an icosahedral phage head with 5-fold symmetry.

After maturation of virus particles, the cell is lysed by lysins, holins, or a combination of the two.

[2] For most of virological history, Caudoviricetes which was known as the order Caudovirales, had lower taxa defined via morphology and contractile ability of their "tails".