Which literary device compares two unlike things without using 'like' or 'as'?

A metaphor is a literary device that directly compares two unlike things without the use of "like" or "as." This form of comparison creates a more implicit relationship between the two subjects, allowing for a deeper understanding or new insight into the characteristics of the items being compared. For instance, saying "Time is a thief" suggests that time, like a thief, can steal moments from our lives, highlighting its elusive and often unnoticed nature.

In contrast, similes, which also make comparisons, specifically use "like" or "as," making their comparisons more explicit. Alliteration refers to the repetition of initial consonant sounds in a sequence of words, often used for poetic effect, while personification attributes human characteristics to non-human entities, adding emotional depth to descriptions but not functioning to make direct comparisons. Thus, the nature of a metaphor uniquely allows for a nuanced exploration of concepts that enhances the reader's experience.