The Copyright Act includes a face-to-face teaching exemption (§110) for the performance or display of videos in a classroom where instruction occurs.
If you teach online, you'll want to examine the TEACH Act. The TEACH Act allows for limited portions of videos and audio to be played or embedded in an online class if the video was legally acquired and is integral to the course content. You can read more about the application of the TEACH Act for online instruction in this recent Library of Congress blog post, TEACHing from a Distance and Copyright Considerations.
If you find a video in one of the library's video databases, you can embed those in Canvas or provide links to them without violating copyright.
Face-to-Face
The Copyright Law (Title 17, United States Code, Section 110) exception for classroom use allows instructors or students to use audio-visual materials in the course of face-to-face teaching activities in a nonprofit educational institution (in a classroom or similar place devoted to instruction).
Online
Instructors may use portions of legally obtained videos critical to course content. You may also embed or steam any videos from library database such as Kanopy.
It depends!
If you want to show videos outside of the classroom setting, you must first obtain Public Performance Rights (PPR).
Public Performance Rights (PPR) are a special license that is either purchased with a video or separately from the video to allow the video to be shown outside of personal home use. This statute applies to all videos currently under copyright, including videos you have purchased, borrowed from the library, or rented from a video store or services like Netflix.
Some materials in the library already include Public Performance Rights (PPR), including videos within Kanopy and several DVDs within the library's collection. The PPR related to Kanopy stipulate that the showings must be on campus at Cal State LA and charge no admission.
However, most feature films and videos do not automatically include Public Performance Rights.
If you want to have a public showing of a film that is not part of the library's PPR collections (such as Hollywood Feature Films) you need to obtain Public Performance Rights (even if no admission is charged). The following licensing companies sell public performance rights.
Library DVDs purchased from the vendors include Public Performance Rights and may be shown to groups without any additional licensing.
What are Public Domain movies?
Public domain movies are not protected by copyright either because they were never copyrighted or their copyright term has expired. Films in the Public Domain can be shown anywhere without the need to obtain Public Performance Rights. Unfortunately, many PD films available online or on DVD have rather poor audio/video quality.
Here are some web sites that list movies in the Public Domain:
Creative Commons is a nonprofit organization that has created licenses that work in conjunction with copyright law to allow creators to specify how they will allow others to use their works without seeking permission. You can use works licensed under Creative Commons without seeking permission from the copyright holder as long as you follow the license terms.