So, in the labour market there are firms that demand labour to be able to produce the goods that they sell, and there are workers who supply labour in order to earn a wage. First let’s think about the worker, and imagine that you are comparing the number of hours that you would work to the wage that you will earn. Would you be more willing to work more if you were paid £4 an hour or £20 an hour? £20 an hour right? So you can say that the higher the wage, the more employment there is, and we can show this through a graph: (I would then draw the Labour suply curve with axes of wages and employment - I can’t see the tool to do it now).
Now let’s look at the people who are demanding this labour that people are supplying, the firms. If you’re a company would you hire more people if they cost you £4 per hour or £20 per hour? £4 per hour right? - you want cheap labour and if labour is too expensive then it’s either cheaper to buy a machine to do the job instead of the worker (e.g. buying a combine harvester because it’s actually cheaper than hiring 50 people to do the same work), or it might not be worth hiring the worker at all (e.g. if a builder wants £30 per hour to work for your construction company, but your client is only paying you £20 per hour for the job, then you actually lose money by hiring the builder! - And so you won’t hire them because the wage is too high)
All this to say that the higher the wage, the less workers the firm will hire, and we can also show this in the same graph: (Add labour demand curve to the graph).
Now, as you know from the very start of your economics course, the market will then stabilise to a point where exactly the same number of people are willing to supply labour for a given wage as the firm is willing to hire for that wage (Show on diagram). This is the equilibrium level of wages in the economy, where everyone who wants to work (for the offered wage) has a job.
(The labour market is way more complicated so I would then spend the whole lesson explaining all the aspects of it :) )