When you sell an asset before the end of its useful life, you might make an accounting gain or a loss on that sale. For example if you sell the company computer for £400 and at the time after depreciation it is worth £300, the gain of £100 will be allocated to this account.

Gain - Say you sold an asset on eBay for £800 and the carrying value is £600 at the time you sell it. You'll have a £200 gain on sale.

Loss - Say you sold an asset on eBay for £500 and the carrying value is £600 at the time you sell it. You'll have a £100 loss on sale.

Depreciation is not considered a loss on an asset.