The term "virtual particles" refers to entities in quantum field theory (QFT) that appear in Feynman diagrams as internal lines without free ends, representing interactions between real particles. They are not directly observable and arise during perturbative expansions, serving as mathematical tools rather than physical entities. The concept is often misunderstood, as virtual particles do not exist in the same way as real particles; they are a product of the perturbation theory used in QFT. Discussions highlight that while virtual particles facilitate understanding interactions, they challenge traditional notions of energy conservation due to their transient nature. Ultimately, the notion of virtual particles is a linguistic convenience that aids in the interpretation of quantum mechanics and field theory.