Bootstrap offers a set ofresponsive utility classes so that you can control the visibility of certainelements. Now these classes allow you to turn visibility on or off, dependingon certain responsive breakpoints, or, when the user tries to print out thepage.
The formula for doing this looks like this. You specify a visibility keyword, and that’s visible, or hidden. Then you add a size, and those correspond to the responsive grid, so the options are the same as any of the grid breakpoints, that’s XS, SM, MD, LG, and there’s also an option to specify print as a breakpoint.
Which means that the element will be visible, or hidden, when somebody tries to print out the page. Finally, if you’re specifying that something needs to be visible at a specific breakpoint, or for print, you can optionally provide information about the display element for that breakpoint.
So you can ask the element to display as a block element, an inline element, or, an in-line block element. Or you can specify that the element only shows up.