You need to cite things and give their creators credit. When you do this, you prevent plagiarism. Plagiarism is taking someone else´s work as your own. If you don´t cite where you got your media, you could get fined and even arrested if it is a major offense. All you have to do to cite is write the owners name next to the image or someplace on your presentation if you used website for information. Attribution is the same thing. It´s easy! Give people their credit for what they made, don´t pass it of as your own. Also, as further warning, don´t photograph or record people without them knowing. That is a SERIOUS offense and illegal.
The pumpkin is smiling,
a toothy grin, he grabs his belly,
as he smiles with delight,
He is laughing and smiling,
a big, grand grin, for he is taking a picture, for Halloween night
See how I gave the owner and maker of this photo credit with Compfight? Do it like this, near the picture.