I want to learn how to make these types of messages, is it a modal?
some example? Is it only css? what libraries are used to do it? jquery?
Yes, with tooltips.
If you put the mouse over the Javascript label of your question, when the floating box comes out, you give a right button and inspect the element you can see that this code is generated:
<div style="overflow: hidden; position: absolute; z-index: 1002; width: 350px; height: 165px; top: 455px; left: 76px;"><div id="tag-menu"><div>
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What you have to do is make an event (onMouseOver for example) that collects the positions of the element it is on and puts a% floating% of it there (with innerHTML or you have created it and with the onMouseOver you make it visible) with the information you want to add
Example
.tooltip {
position: relative;
display: inline-block;
border-bottom: 1px dotted black;
}
.tooltip .tooltiptext {
visibility: hidden;
width: 120px;
background-color: black;
color: #fff;
text-align: center;
border-radius: 6px;
padding: 5px 0;
/* Position the tooltip */
position: absolute;
z-index: 1;
}
.tooltip:hover .tooltiptext {
visibility: visible;
}
<p>Pon el raton sobre el texto de abajo:</p>
<div class="tooltip">Pasa el cursor
<span class="tooltiptext">TEXTO
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In this page you will see more properties and functions working with tooltips