It refers to the process of changing the domain registrar managing a domain.
It is usually a simple process but takes a few days – from six days for completion.
The process involves the holding domain registrar unlocking the domain and submitting a transfer code popularly known as EPP code. This is a simple code that that is used to verify the domain transfers process.
The Receiving Domain Registrar is supposed to feed the incoming domain at the domain management portal as a transfer, then verify by feeding the EPP code.
It may be free or attract a fee, when it attracts a fee it is usually a domain renewal fee and therefore in that case the domain is transferred and renewed for a year.
When it’s free, old expiring dates remain.
International domains usually attract a transfer fee and therefore complete transfers include domain renewal at least for a year.
As for .KE domains transfers in Kenya charge or no charge option differ with the domain registrar, some registrar charge, other do not, and therefore do not renew the domain upon transfer.