As the name suggests, total return is the whole return delivered by an asset over a period of time. As such, it includes capital return (delivered by change in the price of that asset) and income.
For example, if you invest £100 in a fund and by the end of the first year its value has increased to £108, then the capital return for that period will be 8%. If the fund also delivered £2 of income during that year, that would equate to a yield of 2% on the original £100 invested. Including that extra 2% of income in the return calculation gives a total return of 10% (8% capital return + 2% income return = 10% total return).
For any asset that delivers a reasonable income stream, such as an equity income fund, the difference between capital and total return becomes very significant over long periods of time. That is the magic of compounding – Einstein’s eighth wonder of the world.