A branch is an affiliate of another company whether registered in Kenya or a foreign company while a subsidiary is a local company registered as its own entity where the major shareholder is another company (the parent/holding company).
The tax implications of a branch in Kenya is that it will be subjected to corporate tax at the rate of foreign companies which is 37.5% while a subsidiary is taxed at the rate of a local company 30% corporate tax rate.
The employees are taxed based on their resident status, if foreign at foreigners rates while the income of local employees will be at citizens rates.