Capital gains are the profits derived when an investor sells the capital asset and makes a profit. Capital Gains Tax is only triggered when an asset is realized, not while it is held by an the asset is sold and not until it is sold.
CGT can impose significant costs when an asset is moved into or out of a company or otherwise disposed of.
For example, if a property is moved into a company this can trigger a CGT charge payable that year. If the property is transferred out at some future time them more CGT may be payable by the recipient at that time.
Careful planning, including the use of Limited Liability Partnerships, will mitigate the Capital Gains Tax due, and in some cases eliminate it altogether.
As with all tax matters. The earlier this is planned and acted on the better.