Explanation
Embedded Chat Service is a feature that can meet the requirement of allowing customers to interact real time with support agents from their computers and mobile devices. Embedded Chat Service allows administrators to embed a chat widget on any web page or mobile app that customers can use to start a live chat session with an agent. Embedded Chat Service also supports features such as pre-chat forms, chat transcripts, file transfer, and chat transfer. Verified References: :
https://help.salesforce.com/s/articleView?id=sf.snapins_chat_overview.htm&type=5 :
https://help.salesforce.com/s/articleView?id=sf.snapins_chat_setup.htm&type=5

Explanation
A Lightning email template is a type of email template that can be used to create and send emails from Salesforce. A Lightning email template can include merge fields, images, links, and other formatting options.
A Lightning email template can also include a knowledge article as an attachment or a link. A consultant can configure a Lightning email template to send the article to the customer by selecting the Knowledge Article option in the template editor and choosing the article to include. The agent can then use the template to send an email with the article to the customer from the case record page or the Service Console. Verified References: Service Cloud Consultant Certification Guide & Tips, Create Lightning Email Templates

Explanation
The Lightning Service Console is a user interface that allows you to manage multiple records on one screen and quickly access important information. You can use tabs and subtabs to organize your records and switch between them easily. To meet the requirement of viewing the case history of other cases for the same account when viewing a case, you can use account tabs with case subtabs. This means that you open an account record as a primary tab and then open related cases as subtabs under that account tab. This way, you can see all the cases for that account on one screen and compare their case histories. Verified References: [Tabs and Subtabs in Lightning Console Apps]