How to add a search bar in HTML?

It can be added using the form tag in HTML. Here is a simple code sample:

```

```
In this code, “/search” is the destination url that the search queries will go. The “q” parameter passed in the input name is a common way of denoting a search query.

The “placeholder” attribute is used to display hint text in the input field before the user enters a value.

The submit button initiates the search action when clicked. You can replace “Go” with any text you want to display on the button.

Remember to replace the “/search” in the action attribute with the actual location where you want to send the user’s input from the search bar.

This code creates a basic search bar. However, the functionality of accepting and processing the search query needs to be implemented on the server side by using backend languages like PHP, Python, Node.js etc.