Explanation
IP address restrictions allow you to prevent users from accessing Salesforce from outside of their network.
You can set IP address restrictions on the profile level or globally for the org. To enforce IP restrictions for API logins, you must select Enforce Login IP Ranges on Every Request in Session Settings.
References: https://help.salesforce.com/s/articleView?id=sf.security_networkaccess.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.security_enforce_ip_ranges.htm&type=5

Explanation
Lead assignment rule is a feature that can be used to route new leads to the correct sales person based on the lead address. Lead assignment rule can assign leads to users or queues based on certain criteria, such as lead source, industry, or location. Lead assignment rule can also send email notifications to the new lead owners or other recipients. References:
https://help.salesforce.com/s/articleView?id=sf.leads_assignment_rules.htm&type=5

Explanation
Default language and currency locale are two options that an administrator should configure in the company settings to support a global team of Salesforce users. Default language determines the language that is used for labels, buttons, tabs, help text, and messages in Salesforce for all users unless they override it in their personal settings. Currency locale determines the format of currency fields and numbers in Salesforce for all users unless they override it in their personal settings or enable multiple currencies. References:
https://help.salesforce.com/s/articleView?id=sf.admin_supported_languages.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.admin_supported_currencies.htm&type=5

Explanation
Security Health Check is a tool that can be used to identify and fix potential session vulnerabilities. Security Health Check scans the security settings in an org and compares them to a baseline set of standards, such as the Salesforce Baseline Standard or the Salesforce Optimized Standard. Security Health Check provides a health check score and a list of issues and recommendations for improving the security settings. References:
https://help.salesforce.com/s/articleView?id=sf.security_health_check.htm&type=5

Explanation
Big Deal Alerts allow you to notify users when an opportunity reaches a certain amount or probability.
References: https://help.salesforce.com/s/articleView?id=sf.forecasts3_big_deal_alerts.htm&type=5