Quantum Fourier Transform (QFT) is a way of representing information in the form of a special pattern of numbers. This pattern is like a puzzle, and when pieces of it are put together correctly, it can help scientists and mathematicians solve difficult problems. You could think of it like a toy cubed puzzle, where each of the pieces have a number on them. When you put all the pieces together in the right order, it creates a picture - in this example, it might be the face of a favourite character.
QFT works in a similar way, except instead of pieces of the puzzle being numbers they are called qubits. Each qubit has a special number, and when put together in a certain order, they can form a pattern. This way of putting numbers together helps scientists and mathematicians solve complicated problems.