AI produces some of the content you consume, which is why identifying AI is important for your efficacy as an engaged citizen and your development as a knowledgeable professional. Below are some ways to identify AI-generated content (for now). As AI rapidly becomes more sophisticated, these tactics will become outdated and need to adjust. Which is why you should always verify information you find online or in AI outputs.
Text
Some identifying features of AI generation: very formal tone and grammar, use of professional jargon, no typos. However, this information is verifiably accurate! Your library is the best resource for navigating databases and research assistance.
Image 
Some identifying features of AI generation: glossy/airbrushed textures, physics defying features (person's left hand isn't supporting the saucer, light fixture is hanging from an unspecified source, ceiling tiles are wavy), inconsistent lighting (shadow of cup vs shadow of falcon).
Video/Audio
Unnatural cadence, odd inflection, subtle misalignment of mouth shape to words spoken.