Hello there,I am learning the bootstrap3 templates,in portfolio template there are several image block containing <img src="https://placehold.it/150x80?text=IMAGE" class="img-responsive" style="width:100%" alt="Image">
So,I want to know what is the meaning of these placehold.it and 150x80 where did it come from?
from where I can learn this entire topic.
please help me as soon as possible..