Particles can't be seen- which is a big problem for physicists- but they need to detect them somehow to know their attributes. In the nature some animals detect the world with the help of photons which can be found in the light. We humans do the same. Light has wave characteristics which means it can reflect from surfaces and by this you can sense the object from the direction of photons which come into your eyes or you can tell oder properties of the object by the different wavelength of the photons. Some animals such as dolphins or bats do the same with sound.
However, the quality of the image you detect by your eye is limited by the wavelength. Because we can only see visible light which has a wavelength around 0.0000005 meters. This means we can contrast two points which are 0.0000005 meters far from each other. Eventually, this size is much too big compared to particle-sizes. With a shorter wavelength physicists can detect particles. As long we know that particles have wave characteristics too, physicists can use them by detecting other particles that interact with the probes. To sense the most tinyest particles, physicist use accelerators to decrase their wavelength. (Due to de Broglie's a bigger velocity comes with a shorter wavelength.)