Hi @Akansha, wildcards are basically Symbols which are used with Selectors that changes dynamically. Mainly there are 2 wildcards:
1. Asterisk (*): It is used for replacing 1 or more characters from a selector attribute. For Eg. <title="abc-zyx"></title> is an attribute which changes dynamically, every time you open a specific webpage. So if you want your selector to identify the webpage by <title> tag then replace the <title> this way: <title="*"></title>. Now even if the title of a webpage changes every time it gets refreshed, your Selector would identify which element to select.
2. Question Mark (?): It is used to replace a single character from the selector attribute. For eg. If a webpage opens pages with a counter at the end of title like <title="abc-1"></title> or <title="abc-2"></title>, then in that case you can replace the title value this way: <title="abc-?"></title>.
These are really useful in web scrapping where selectors might need to modify the attributes to identify dynamically changing values.