A Custom PC is a personal computer that is built according to the specific preferences and requirements of the user. Unlike pre-built systems, a custom PC allows individuals to choose each component, such as the CPU, GPU, motherboard, and RAM, ensuring optimal performance for tasks like gaming, graphic design, or general use. Building a custom PC can be a rewarding experience, as it enables users to tailor their system to their needs and budget. Additionally, it often results in better performance and upgradeability compared to off-the-shelf models, making it a popular choice among tech enthusiasts and gamers.