Simile

When a comparison of two things is made, indicated by some linking words (i.e. like, as, than or a verb such as resembles) it is a simile.  A simile conveys a similarity clearly. Still, for a simile to exist, the things compared have to be dissimilar in kind. It won’t be a simile if it is said “Your face is like mine”.

Examples of Simile:

Life like a dome of many-colored glass,

Stains the white radiance of Eternity.                                        
(Shelley- Adonais)

To follow knowledge like a sinking star.                            
(Tennyson- Ulysses)

Higher still and higher

From the earth thou springest

Like a cloud of fire.                                                       
(Shelley- To A Skylark)

The ice mast-high came floating by

As green as emerald.                                             
(Coleridge- Ancient Mariner)

In the first example, life has been compared to a dome both of which are dissimilar in kind. In the second one, knowledge has been compared to a sinking star. Likewise, in the third example, poet compares the Skylark to a cloud of fire.