Before starting, I hope you have an Azure Subscription. If you don’t have one, create a free account here. This bot is created using azure services. If you want to create flight booking bot using the C# template using Bot Builder SDK in Visual Studio, go to my post.
A bot is an app that users interact with in a conversational way, using text, graphics (such as cards or images), or speech. Every interaction between the user and the bot generates an activity. The Bot Framework Service, which is a component of the Azure Bot Service, sends information between the user's bot-connected app (such as Facebook, Skype, etc. which we call the channel) and the bot.