When a person uses the phrase ‘by hand’ they are usually indicating that the particular task was done by human hands and not with the help of technology or machines. That is, the particular task was done manually.  It also means that a particular thing was sent to someone personally rather than sending it via a third person or system. ‘The dough was rolled by hand’ ‘The jewelry is created by hand’ ‘He sent him the papers by hand’ The phrase ‘by hand’ is therefore used to indicate when someone does something with their own hands rather than using machines. It is also used to indicate when something was sent to someone personally rather than through a system.