This is my FAVORITE TOOL! I love love LOVE showing videos in my classroom, and my students LOVE watching videos. I feel videos can provide a different perspective for students. I can teach students and they listen..but after a certain point, their attention is not fully there, so we as teachers have to constantly be changing our teaching style within even one lesson, to keep them engaged. A video is a perfect way to do so. I love using videos throught the class, I could show a video to introduce a topic, to reinforce concepts or use it as a "wrap up" to a lesson or even a unit. Videos can be used as good reviews for upcoming tests also.
The two sources I used a lot this year for videos were Brainpop/Brainpop Jr., and Discovery Education. Brainpop Jr. was a great tool to use to introduce new concepts to students (even though it's meant for K-3) it's a great tool for ELL's, and a great way to start building the foundation students need for the topic. Brainpop was also very good but would not go into as much detail about topics learned in the fourth grade, and vocabulary was sometimes very high level (mostly middle school/highschool) but a great source to use at the end of a lesson/few lessons to move students to a higher level.
Discovery Education is wonderful because you find sooo many videos on there for every subject, "real" videos. I used Discovery Education a great deal during science. We would watch informational videos, videos that would show us different experiments (which was great, in case we did not have time, or if we had done the same experiment and discuss how we could have done it differently).
I got this video from Brainpop Jr. I used this video with my students to teach them about the phases of the moon. This concept is SO difficult for students to understand because they do not see the Earth rotating around the sun, and the moon. This video is a fun way to show the different phases of the moon, and why we have these phases.
This video I downloaded from youtube. I love using songs in my classroom as much as I love using videos. This is a Bill Nye water cycle rap. The kids absolutely LOVE this video. They sing along with it, and I could see them mouthing this song as they were taking tests. When we had some free time, or eating lunch together in the classroom, the kids would BEG me to play this watercycle rap for them. They would drop everything, start dancing and singing along to it.
Videos are an interactive way to supplement a lesson :)