I have a client who is questioning my use of the div tag to apply classes to small areas of text such as : <div class="mystyle">text</div>

It works fine but they are implying that it's a bit of a hack - what is the correct usage of this tag? - can anyone tell me what the the div tag stands for and is it compliant/good practice to use it to apply text formatting to a single line of text?

Thanks for any comments.