Simile - a type of figurative language that compares two things by using the words like or as.
Using a simile allows a writer to help their audience understand something by suggesting it is similar to something else.
This technique is similar to a metaphor, although not quite the same as we shall see.
Let's consider a hypothetical example to help us understand how similes work.
Imagine we are writing a story that involves a giant monster destroying a city. In our minds, this creature is just over 800 metres tall, and it is having a fine time stomping on all the buildings underneath it.
To help our reader understand just how tall this monster is, we could use literal language to write the following:
The monster was over 800 meters tall and destroyed the buildings beneath it.
Not bad, but our audience may have trouble picturing just how high 800 meters is (plus the sentence isn't very interesting).
Let's try a simile to see if we can make our writing more meaningful.
It turns out that the highest building in the world, the Burj Khalifa in Dubai, is 829 metres high. Therefore, we could write about our monster like this:
The monster was as tall as the Burj Khalifa and destroyed the buildings beneath it.
Better, but still not as interesting as it could be. Let's see if we can spice it up a little more and add another simile into the mix.
The monster towered above the city skyline like the Burj Khalifa, and crushed the buildings beneath it as easily as a child stomping on sandcastles.
That's a bit more like it. Our sentence is now more evocative thanks to the use of two similes (consisting of both like and as to mix things up), plus we have used more specific vocabulary in the form of the verbs towered and stomping.
Compared to our first attempt, this sentence has a greater sense of drama, and it helps the reader to appreciate the scale of the giant monster as it goes about its rampage.
Similes are a helpful way to recreate whatever is in the mind of the writer in the mind of the reader. Because the reader cannot "see" whatever the writer is thinking, meaningful comparisons help to bridge this gap.
Remember, similes rely on the reader being aware of whatever it is that is being referred to. If the comparison made by the writer is not clear, the reader will become confused.
Regarding the example we used above, however, I think we're pretty safe because the Burj Khalifa is very well known, and most of us have stomped on a sandcastle at some point...