These are investment packaging, not direct investments.
Unit trusts are funds that are divided into units, where each unit represents a proportion of the fund (basically, the value of the fund’s assets divided by the number of units gives the unit price). To help cover expenses there is normally around 5% difference (spread) between the price that investors pay for units, and the price at which they sell them back.
A unit trust can be set up to invest in pretty well any area it likes, so it is very important that you understand the investment strategy being pursued by the managers.
The value of investments and income from them can fluctuate (this may partially be the result of exchange rate fluctuations), and investors might not get back the full amount invested. Past performance is not a guide to future performance.