HTML entities are special characters that cannot be directly included in HTML code. Instead, they are represented by entity names or numbers. This is necessary because HTML code uses certain characters for its own purposes, such as < and > for tags and & for character references.

Using HTML entities allows for the display of special characters such as copyright symbols, foreign language characters, and mathematical symbols. Here are some of the most commonly used HTML entities and their corresponding entity names and numbers:

1. Special Characters

• & (ampersand)
• < (less than)
• > (greater than)

2. Accented Characters

• á (á)
• é (é)
• í (í)
• ó (ó)
• ú (ú)
• ñ (ñ)

3. Mathematical Symbols

• ± (±)
• × (×)
• ÷ (÷)
• √ (√)
• π (π)

4. Currency Symbols

• $ ($)
• £ (£)
• € (€)
• ¥ (¥)

When writing HTML code, it is important to use HTML entities for any special characters that may be needed in the content. Additionally, it is important to properly encode any user-generated input to prevent security vulnerabilities such as cross-site scripting attacks.

In terms of good practices for writing HTML code, it is recommended to use semantic markup to provide meaning to the content and structure of a webpage. This includes using appropriate HTML tags for headings, paragraphs, lists, and other content elements. It is also important to use valid HTML code by following the rules and guidelines set forth by the W3C (World Wide Web Consortium). This ensures that the code will be rendered correctly across different devices and browsers.

Furthermore, it is recommended to use external CSS files to style the HTML code, rather than using inline styling or deprecated HTML tags such as <font> or <center>. This separates the content from the presentation and makes it easier to update the styling of a webpage. It is also important to optimize images and other media for web use, to improve page load times and overall user experience.

Overall, using HTML entities and following good practices for writing HTML code are important steps in creating accessible, well-structured, and properly formatted webpages.

HTML character entities are codes that represent special characters that cannot be easily typed or displayed in HTML documents. These entities are used to ensure that the HTML code is valid and to display characters that are not normally available on a keyboard.

There are several types of HTML character entities, including:

1. Numeric character entities: These are represented by a decimal or hexadecimal code, such as A or A for the letter “A”.
2. Named character entities: These are represented by a name that corresponds to the character, such as © for the copyright symbol ©.
3. Special characters: These are represented by a combination of characters, such as < for the less than symbol <.

Here is a list of commonly used HTML entities:

• < – less than sign (<)
• > – greater than sign (>)
• & – ampersand (&)
• ” – double quotation mark (“)
• ‘ – single quotation mark (‘)
• ¢ – cent sign (¢)
• £ – pound sign (£)
• ¥ – yen sign (¥)
• € – euro sign (€)
• © – copyright sign ©
• ® – registered trademark ®
• ™ – trademark ™
•   – non-breaking space
• – – en dash (–)
• — – em dash (—)
• ‘ – left single quotation mark (‘)
• ’ – right single quotation mark (’)
• “ – left double quotation mark (“)
• ” – right double quotation mark (”)

It is important to use HTML entities correctly in your code to ensure that your document is valid and displays correctly. When using named entities, it is important to ensure that they are supported by all browsers and that the corresponding character is displayed correctly.