The reason why a trader trades in the market is to make profits.

Support and resistance is a very important part of technical analysis but what actually makes these levels? It is the psychology of the traders that forms the support and resistance levels.
There is a reason why the support and resistance level actually works. Price touches these levels and rebounds from these levels. This is because of the psychology of the participants in the market.
The reason why a trader trades in the market is to make profits. They may also be trading to make up for the loss in the last few trades.
Basically the trader’s mentality is divided into those who are long on the position, those who are expecting that the price of the security will fall and are short on the position and those who do not know what is happening and are thus are undecided about where to trade or whether to trade in the security now.
The stock trades between the support and the resistance levels. The support is the demand from where the stock prices will go up. The resistance is the supply from where the stock price will go down.
When the price starts to move up from the level of support the long traders are now happy and they wish that they could buy more. They thus wait for the price to return back to the level of support so that they can increase their positions.
The short traders on the other hand are not happy with the decision that they have taken because they are losing money as the trade is not working in their favor. They hope that the price of the stock will fall down so that they can cover their position by buying the stock. In this way they will not lose a lot. You can always read up more info on this.
Those who were undecided about taking the trade repent on having missed the trade. They are hopeful that the price will come down again and this time they are not going to let the trade go. They thus decide to buy the stock at the lower level.
So basically the complete set of traders who form the market are looking at that level from where they want to buy the stock. They are decided that they will buy the stock when the price touches the level. This is a very simple explanation of the psychology of a support level.