No, not every PC needs a graphics card. Depending on the type of PC and the types of tasks it is intended to perform, some PCs may be able to get by without a separate graphics card. PCs used for internet browsing and basic office applications usually don't need a graphics card. On the other hand, PCs used for gaming, video editing, and other graphically intensive tasks will generally require a dedicated graphics card to get the best performance.

I hope this will clear your doubts, thank you for posting.