A plethora is an overabundance or extreme excess, especially of information. It refers to a large or excessive amount. The example given uses plethora to describe there being a very large amount of both useful information and misinformation available on a topic.

1. plethora
[pleth-er-uh]
- noun (usually followed by ‘of ’)
overabundance, extreme excess
“there is a plethora of
information and misinformation”