What are the chat launch and landing pages? 

Environment:

B2C Service Chat
Customer Portal, Chat - Enduser Pages

Resolution:

The chat_launch page is used to collect the customers information before launching the actual chat. After the user chooses to start a chat, they will be re-directed to the chat_landing page.

Below are related published answers:

Contact Fields on the Chat Launch Form

Passing custom fields from a chat launch URL to a resulting chat and incident

Visibility settings with incident custom fields specific to chat

Adding and customizing fields on chat_launch page

See also:  Answer ID 4725: Popular Answers About Chat.

For additional information, refer to the 'Chatting on the Customer Portal' section in the Online Help User Guide documentation. To access Oracle B2C Service manuals and documentation online, refer to the Documentation for Oracle B2C Service Products.