What causes a toilet to gurgle and how can it be fixed?

A toilet gurgles when there is a blockage in the Plumbing system, causing air to be trapped and released through the toilet. To fix this, try using a plunger to clear the blockage or a plumbing snake to remove any obstructions in the pipes. If the issue persists, it may be necessary to call a professional plumber to assess and fix the problem.