[css] How to write a caption under an image?

I have two images that need to kept inline; I want to write a caption under each image.

<center>
   <a href="http://example.com/hello">
       <img src="hello.png" width="100px" height="100px">
   </a>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
   <a href="http://example.com/hi">
       <img src="hi.png" width="100px" height="100px">
   </a>
</center>

How can I implement?

The <figcaption> tag in HTML5 allows you to enter text to your image for example:

<figcaption>
Your text here
</figcaption>.

You can then use CSS to position the text where it should be on the image.

<div style="margin: 0 auto; text-align: center; overflow: hidden;">
  <div style="float: left;">
    <a href="http://xyz.com/hello"><img src="hello.png" width="100px" height="100px"></a>
    caption 1
  </div>
 <div style="float: left;">
   <a href="http://xyz.com/hi"><img src="hi.png" width="100px" height="100px"></a>
   caption 2                      
 </div>
</div>

CSS

#images{
    text-align:center;
    margin:50px auto; 
}
#images a{
    margin:0px 20px;
    display:inline-block;
    text-decoration:none;
    color:black;
 }

HTML

<div id="images">
    <a href="http://xyz.com/hello">
        <img src="hello.png" width="100px" height="100px">
        <div class="caption">Caption 1</div>
    </a>
    <a href="http://xyz.com/hi">
        <img src="hi.png" width="100px" height="100px"> 
        <div class="caption">Caption 2</div>
    </a>
</div>?

?A fiddle is here.

<table>
<tr><td><img ...><td><img ...>
<tr><td>caption1<td>caption2
</table>

Style as desired.

Put the image — let's say it's width is 140px — inside of a link:

<a><img src='image link' style='width: 140px'></a>

Next, put the caption in a and give it a width less than your image, while centering it:

<a>
  <img src='image link' style='width: 140px'>
  <div style='width: 130px; text-align: center;'>I just love to visit this most beautiful place in all the world.</div>
</a>

Next, in the link tag, style the link so that it no longer looks like a link. You can give it any color you want, but just remove any text decoration your links may carry.

<a style='text-decoration: none; color: orange;'>
  <img src='image link' style='width: 140px'>
  <div style='width: 130px; text-align: center;'>I just love to visit this most beautiful place in all the world.</div>
</a>

I wrapped the image with it's caption in a link so that no text could push the caption out of the way: The caption is tied to the picture by the link. Here's an example: http://www.alphaeducational.com/p/okay.html

For responsive images. You can add the picture and source tags within the figure tag.

<figure>
  <picture>
    <source media="(min-width: 750px)" srcset="images/image_2x.jpg"/>
    <source media="(min-width: 500px)" srcset="images/image.jpg" />
    <img src="images.jpg" alt="An image">
  </picture>
  <figcaption>Caption goes here</figcaption>
</figure>

Figure and Figcaption tags:

<figure>
    <img src='image.jpg' alt='missing' />
    <figcaption>Caption goes here</figcaption>
</figure>

Gotta love HTML5.

See sample

#container {_x000D_
    text-align: center;_x000D_
}_x000D_
a, figure {_x000D_
    display: inline-block;_x000D_
}_x000D_
figcaption {_x000D_
    margin: 10px 0 0 0;_x000D_
    font-variant: small-caps;_x000D_
    font-family: Arial;_x000D_
    font-weight: bold;_x000D_
    color: #bb3333;_x000D_
}_x000D_
figure {_x000D_
    padding: 5px;_x000D_
}_x000D_
img:hover {_x000D_
    transform: scale(1.1);_x000D_
    -ms-transform: scale(1.1);_x000D_
    -webkit-transform: scale(1.1);_x000D_
    -moz-transform: scale(1.1);_x000D_
    -o-transform: scale(1.1);_x000D_
}_x000D_
img {_x000D_
    transition: transform 0.2s;_x000D_
    -webkit-transition: -webkit-transform 0.2s;_x000D_
    -moz-transition: -moz-transform 0.2s;_x000D_
    -o-transition: -o-transform 0.2s;_x000D_
}

<div id="container">_x000D_
    <a href="#">_x000D_
        <figure>_x000D_
            <img src="http://lorempixel.com/100/100/nature/1/" width="100px" height="100px" />_x000D_
            <figcaption>First image</figcaption>_x000D_
        </figure>_x000D_
    </a>_x000D_
    <a href="#">_x000D_
        <figure>_x000D_
             <img src="http://lorempixel.com/100/100/nature/2/" width="100px" height="100px" />_x000D_
            <figcaption>Second image</figcaption>_x000D_
        </figure>_x000D_
    </a>_x000D_
</div>

To be more semantically correct and answer the OPs orginal question about aligning them side by side I would use this:

HTML

<div class="items">
<figure>
    <img src="hello.png" width="100px" height="100px">
    <figcaption>Caption 1</figcaption>
</figure>
<figure>
    <img src="hi.png" width="100px" height="100px"> 
    <figcaption>Caption 2</figcaption>
</figure></div>

CSS

.items{
text-align:center;
margin:50px auto;}


.items figure{
margin:0px 20px;
display:inline-block;
text-decoration:none;
color:black;}

https://jsfiddle.net/c7borg/jLzc6h72/3/

CSS is your friend; there is no need for the center tag (not to mention it is quite depreciated) nor the excessive non-breaking spaces. Here is a simple example:

CSS

.images {
    text-align:center;
}
.images img {
    width:100px;
    height:100px;
}
.images div {
    width:100px;
    text-align:center;
}
.images div span {
    display:block;
}
.margin_right {
    margin-right:50px;
}
.float {
    float:left;
}
.clear {
    clear:both;
    height:0;
    width:0;
}

HTML

<div class="images">
    <div class="float margin_right">
        <a href="http://xyz.com/hello"><img src="hello.png" width="100px" height="100px" /></a>
        <span>This is some text</span>
    </div>
    <div class="float">
        <a href="http://xyz.com/hi"><img src="hi.png" width="100px" height="100px" /></a>
        <span>And some more text</span>
    </div>
    <span class="clear"></span>
</div>