Capital Gain Tax is that tax which you pay on the profit you get after selling/disposing of your property. The property includes buy-to-let properties, lands, business premise, any other kind of property. Capital gain is the amount you pay on the profit you get after selling the property. It is not on the amount you receive after selling the property. The below article makes it clear which property is liable to capital gain tax and which not.
Selling Your Home
When you sell your home, any gain you make is tax-free if you have lived there for the entire period you owned it. If you occupied the property as your main home(or elected for it to be treated as your main home) for just part of the time you owned it, the gain made for that period is tax-free, as is the gain made for the last 36 months of ownership. The Government believes that this 36-month rule is not effective. So the government is cutting this tax free period to 18 months for disposals made after 5 April 2014.
Gains Made by Non-residents
If you are not resident in the UK for tax purposes. The profit you make after selling your property in the UK is not liable to tax. Although the gain may well be taxed in the country where you are tax-resident.
From 6 April 2015, gains accruing from that point on homes located in the UK, will be taxed in the UK, where the owner is not resident in the UK. Anyone who emigrates and then sells their former UK home (or investment properties) after living abroad for a while needs to watch out for this.
Social Enterprise Investment
From April 2014 individuals who provide funds for investment in social enterprises will receive some income tax and capital gains tax relief. Further details announced later.
For more detailed information on Capital gain tax visit the UK GOV site.