Every Year we depreciate the fixed assets value as per the 
companies act as companies polacies dep is ( slm or wdm 
methods ).

Accumulated deprciation entry is

Dr Depreciation A/c
Cr Provision for Depreciation A/c

( Being dep for the year accumuated )

Depreciation should be accounted every year, to know the 
exact value of the asset as on particular date. it usefull 
to resale of the asset also.

Depreciation  a/c. (Indirect Expenses)

 to Depreciation Reserve   (Fixed Assets group)

(Being depreciation accounted for the year ....)