A matrix clock is a clock that uses lots of tiny lights or pixels arranged in a grid to display the time.
Imagine you have a big piece of graph paper with lots of small squares on it. Each square is like a tiny lightbulb that can light up or turn off.
Now, to make the matrix clock work, we need to tell the tiny lights which squares to light up at what time. We do this with a computer program, kind of like telling a robot what to do.
The computer program tells each row of squares to light up for a brief moment to show a number, like the number 1. Then it tells the next row to light up for a moment to show the next number, like a 2. This continues until all the rows have lit up to show the current time.
So, if it's 8:45, the program will tell the first row to light up for a brief moment to show the number 8, then the second row to light up to show the number 4, and the third row to light up to show the number 5.
And that's how a matrix clock works! It's like a computer telling lots of little lights what to do to show the time on a grid of squares.