The first half of the 20th century had telegrams and radio, the second half had telephones and television, and the 21st century has the internet and the web. At some point, it is probable that you will want to put up a web page, for which you will need HTML.
It’s a lot simpler than it sounds
HTML stands for ‘hypertext markup language’, which is a set of tags you can use to control where things appear on the page and what they look like. You write them inside pointy-brackets so that the browser knows they are tags. Most of them are quite easy to understand; for example, ‘strong’ means that the enclosed text should appear in bold and ‘li’ means that it should be treated as a list item, helping to line up all your list items for you.
You can write all these tags into a plain page of text. When the browser reads it, it hides all the tags and just shows you the effect on the other words. It is very similar to how word processors work, as they hide the tags that control their fonts and line breaks. On a web page, you can also use HTML tags to position pictures or videos, or even to play sounds or music when the page is opened.
Two problems with HTML
Secondly, if you want to put information from a web page or from a PDF download into a spreadsheet, it will be full of markup and other code. You will need some help to convert HTML or PDF to Excel.
Making HTML even easier
Fortunately, there are online converters that help you to translate documents, databases and spreadsheets directly into HTML web pages or in the other direction; in fact, you can convert almost any format to any other – PDF to Excel, Excel to HTML, Word to HTML, Excel to MySQL, Access to PDF and so on – by using a converter such as https://pdftables.com/convert-pdf-to-excel.
This may sometimes be all you need without having to touch any HTML.