A sonnet is a poetic form that consists of 14 lines, typically written in iambic pentameter. It often follows specific rhyme schemes, such as the Shakespearean or Petrarchan formats. Sonnets usually explore themes of love, nature, or philosophical ideas, allowing poets to express complex emotions within a structured framework. The Shakespearean sonnet is divided into three quatrains followed by a couplet, while the Petrarchan sonnet consists of an octave and a sestet. This form has been used by many famous poets, including William Shakespeare and Petrarch, making it a significant part of literary history.