What's the difference between Telegram groups and channels?

Question: What is the difference between groups and channels?

Telegram groups are great for sharing content with friends and family or collaborating in small teams. But groups can also grow very large, supporting communities of up to 200,000 members. You can make any group public, toggle persistent history to control whether new members have access to earlier messages, and appoint administrators with granular permissions. You can also pin important messages to the top of the screen for all members (including new ones) to see.

Channels are a tool for broadcasting messages to large audiences. In fact, a channel can have an unlimited number of subscribers. When you post in a channel, the message is signed with the channel's name and photo, not your own. Each message in a channel has a view counter that updates as the message is viewed (including its forwarded copies).