Advantage and disadvantage of online sources

Advantage and disadvantage of online sources.
There are various forms of sources available today, one of which is online and offline sources. Both of these types of sources are designed to teach and differ only in the knowledge and level they impart. Both of these forms of sources have advantages and disadvantages. Now I want to talk in my essay mainly about the advantages and disadvantages of online sources.
WHAT ARE THE DIFFERENT TYPES OF ONLINE SOURCES?
E-BOOKS
JOURNALS
WEB PORTALS
SEARCH ENGINES
Advantages of sources are :
Up to date
Easy to access
Inexpensive
Available at all times
And there some disadvantages this sources. They are : unrepresentative samples, lower response rates, financial motivation issues, limited access to certain portals, limited length of study, non-behavioral data, and lack of follow-up data.
So I give information advantages and disadvantages of online and offline sources.