What is a blog?
A blog is a website where written posts and articles are commonly displayed in reverse chronological order. Actually the word "blog" came from "weblog".
At the beginning of blogging people like to use their blogs as personal diaries.
People used blogs to post and share their personal photos, videos, and other information with their friends and family members.
When Google Adsense came into the web world blogs are commercialized. Everyone opening a blog, writing content on their blog and earning a good income by showing relevant ads on their blogs by affiliating with Google Adsense and other Adsense relative programs.
A blog can contain information about any subject, photos, videos, polls. If you want to open a blog and write about your favorite subjects, you can go for www.blogger.com
This has many flexible features than any other blogging platforms.