A comic panel is considered to be a single frame in a multiple-panel sequence. This sequence is used to tell the story.  

 Panels used to tell the story can be   different shapes as sizes, and the standard arrangement used will move the story across the page in a logical fashion.

Notice that the panels are separated from each other by a white frame.  The borders make it easier for readers to distinguish between the events that are taking place in each panel.

Balloons are a means used to make the reading easier because the reader can determine immediately who is speaking and thinking as the action progresses.

Another factor that aids in the reading experience is that balloons are drawn with tails that link to the speaker.  When a panel is filled with a number of speakers and ideas, the tails show the reader who is doing the talking, so the story moves forward easily.  These panels include both speech and interior monologue.

This example from the work of Dave Sim shows the use of speech in a variety of ways.  The style is altered toproduce various types of voices through the balloon differences.

Text plays a number of roles in comics, just as it does in standard literature, but it is used a bit differently in the way it is conveyed.  Text can be speech and is normally located inside balloons.

Usually speech text has a consistent look and style throughout the work, and, as such, creates a strong narrative effect.  In this example Spiderman is doing the talking.

Words used to represent interior monologue is not quite as common as words used for speaking.  Traditionally these words are shown inside balloons with scalloped edges-- meaning this is not audible text.

This is another example of interior monologue that is drawn with the use of color and straight images.  It is clearly not spoken language because there are not tails on the balloons to indicate that there is a speaker.

When narration is used in comics, it is often placed outside the normal space.  Key words such as "later" or "back at home" are often used to express movement of the story.  The comic below shows Stan Lee is talking about what will be happening outside the story.

The content found in comics and graphic novels also includes images, sound effects, and also smells.  The use of these factors creates a feeling of movement that connects the story elements. 

This comic uses the image of the book to connect the elements of the story with the teacher's idea and the resonse of the student.

Comics bring events in the story to life through the use of onomatopoeia, the formation of words in imitation of natural sounds.  The combination of sound through visual images creates motion and interactivity.  These elements definitely spark the imagination and bring the stories to life.

The visual images in this comic demonstrates the power of the creator's idea. Readers can imagine why those who are entering the office would want to wear gas masks. The meaning is clearly conveyed through the combination of the visual image and text.

The use of the sign reinforces the humor involved with the common phrase with which readers are familiar.  The sense of smell is conveyed in more than one way.