Amazon's (NASDAQ:AMZN) fourth-quarter results are out. Though revenue growth decelerated as expected, the top-line figure came in at the high end of management's guidance for the metric. In addition, the company continued to demonstrate its ability to grow its bottom line rapidly.

Here's a look at key figures from the quarter, including the company's double-digit revenue, surging cloud-computing business, revenue guidance, and more.

Boxes in an Amazon fulfillment center.

Image source: Amazon.com.

$72.4 billion

Amazon's fourth-quarter revenue rose 20% year over year, to $72.4 billion. This metric was at the high end of management's guidance for fourth-quarter revenue to rise 10% to 20% year over year to between $66.5 billion and $72.5 billion.

But revenue growth continued to decelerate compared to previous quarters. Amazon's fourth-quarter revenue growth rate was down from 29% year-over-year revenue growth in the third quarter of 2018. Some of this sequential deceleration can be explained by the fact that this was the first quarter in which Amazon was up against a full period of Whole Foods sales in the year-ago quarter. Notably, when excluding revenue from physical stores (a revenue category that primarily consists of Whole Foods), revenue rose 21% year over year during the quarter.

5.2%

Amazon's operating margin, or operating income as a percentage of revenue, swelled to 5.2% -- up from 3.5% in the year-ago quarter. This was driven by outsize revenue growth in Amazon's higher-margin businesses, namely Amazon Web Services.

$3 billion

Net income for the quarter was $3 billion, up from $1.9 billion in the year-ago quarter. This means Amazon's earnings per share increased from $3.75 in the year-ago quarter to $6.04 -- a 61% increase.

46%

The company's cloud-computing business, Amazon Web Services, continued its surging growth. AWS sales were up 46% year over year in constant currency during the quarter. This is in line with the 46% year-over-year revenue growth the segment saw in Q3.

$10.1 billion

Showing just how strong the company's momentum is recently, Amazon's full-year net income was $10.1 billion, or $20.14 per share. This compares to $3 billion, or $6.15 per share in 2017. In other words, Amazon's earnings per share increased 274% in 2018.

$50 billion

In its fourth-quarter update, Amazon provided guidance for its first quarter of 2019. Management expects revenue for the period to rise 10% to 18% year over year to between $56 billion and $60 billion. It expects operating income to rise from $1.9 billion in the first quarter of 2018 to between $2.3 billion and $3.3 billion in the first quarter of 2019.

Check out the latest Amazon earnings call transcript.