Jose wants to know the difference between a TV and a monitor. Leo says that there are huge differences, mainly that TVs simply aren't good enough. TVs don't have as sharp resolution as monitors, which are designed for up-close viewing. That requires a higher than HD resolution. Even up to 4K. TVs tend to be bigger, but the resolution isn't higher as a result, and as such, pixels are easier to see up close. A TV has 100 DPI, while a monitor is 300-400 DPI and a phone 500 and above. The refresh rate is also faster, often twice as much, especially in gaming monitors.
Can he use a TV as a monitor? Sure. Most have HDMI, so it's easier. But it is lower quality and is generally more expensive.