When people talk about the "bottom" in technical analysis, they are usually talking about a point in a stock's price chart where it looks like the price has stopped going down and is starting to go back up.
Imagine you have a toy car that goes up and down on a ramp. If you push the car up to the top of the ramp and then let it go, it will start going downhill and pick up speed. But at some point, it will slow down and start moving up again. The point where it stops going down and starts going up is like the "bottom" in a stock's price chart.
In technical analysis, investors and traders use chart patterns and other tools to try to identify when a stock has hit a bottom and is starting to bounce back. They may look for a series of lower lows and lower highs (which suggests the stock is in a downtrend) and then wait for the price to stop going down and start going up again.
The idea is that if you can identify the bottom of a stock's price chart, you can buy at a lower price and potentially sell for a profit when the price goes back up. However, it's important to remember that technical analysis is not always reliable and there are many factors that can cause a stock's price to go up or down, such as changes in the company's financial performance, industry trends, and global events.