Block level elements normally start (and end) with a new line, when displayed in a browser.
Examples: <h1>, <p>, <ul>, <table>
Inline elements are normally displayed without line breaks.
Examples: <b>, <td>, <a>, <img>
The <div> is a common example of a block level element. The <div> element has no special meaning and It has no required attributes, but style and class are common. The <div> bellow are made vissible with css.
If your not seeing images next to one another try to increase the size of the browser.
Links and span tags are also inline level elemnts, that do not cause a line break.
This link has a span tag applied to part of it This link does not