Hello

To understand the difference between typedef and union, pls go through the spoken tutorial
"Union and Typedef" under the "Advance C" course on our website.

http://spoken-tutorial.org/tutorial-search/?search_foss=Advance+C&search_language=English

<span style="color: rgb(60, 64, 67); font-family: Roboto, HelveticaNeue, Arial, sans-serif; font-size: 18px;">The only </span>difference between<span style="color: rgb(60, 64, 67); font-family: Roboto, HelveticaNeue, Arial, sans-serif; font-size: 18px;"> them is memory allocation. Structure allocates storage space for all its members separately; Whereas, </span>Union<span style="color: rgb(60, 64, 67); font-family: Roboto, HelveticaNeue, Arial, sans-serif; font-size: 18px;"> allocates one common storage space for all its members. Members of a </span>union<span style="color: rgb(60, 64, 67); font-family: Roboto, HelveticaNeue, Arial, sans-serif; font-size: 18px;"> can only be accessed one at a time. The </span>union<span style="color: rgb(60, 64, 67); font-family: Roboto, HelveticaNeue, Arial, sans-serif; font-size: 18px;"> data type was invented to prevent memory fragmentation.</span>

<span style="color: rgb(51, 51, 51); font-family: &quot;Droid Sans&quot;; font-size: 13px;">The keyword Typedef is used to give a new symbolic name for the existing name. </span>