If you are looking for Topics in Salesforce Chatter, then check the following:
CRM Introduction
What is CRM?
CRM Basic entities
Salesforce.com Introduction
What is Salesforce.com?
Why Salesforce.com?
Different editions in Salesforce.com
How to sign up for Developer Edition?
Level 1(Setup and Config)
Types of Objects
1. Standard Objects
2. Custom Objects
Types of Fields
1. Standard Fields
2. Custom Fields
Deployment Status of Custom Object(In Development and Deployed)
Required, Unique and External Id attributes
Required and Read-Only Attributes on the Page Layout
Default Values on the Fields
Formula Fields
Field Dependency
Field History Tracking
Feed Tracking
Dev and Admin Help Community
View setup audit trail
Validation Rules
Email to Case
Web-to-Lead
Web-to-Case
Types of Relationships
1. Lookup
2. Master Detail
Roll-Up Summary Field
Different types of tabs
1. Custom Object Tab
2. Web Tab
3. Visualforce Tab
4. Lightning Component Tab
Types of Applications
1. Custom application
2. Console application
Different types of Email templates
1. Text
2. HTML (using Letterhead)
3. Custom (without using Letterhead)
4. Visualforce
Workflow rules
1. Email Alert
2. Task
3. Field Update
4. Outbound Message
Security and Data Access
1. Organization Wide Default
2. Role Hierarchy
3. Sharing Rules
4. Manual Sharing
5. Object Permission
6. Profiles
7. Permission Sets
8.Account, Opportunity & Case Teams
Renaming Tab Names and Labels
Escalation Rules
Account Hierarchy
Queues
Public Groups
Reports and Dashboards
Scheduling reports
Grant Login Access
Setting IP Ranges
Trusted IP Ranges
Login Hours restriction for Profiles
Approval process
Assignment Rules
Auto Response Rule
Views
Domain Registration
Search Layouts
Search Results
Lookup Dialogs
Lookup Phone Dialogs
Accounts Tab
Accounts List View
Search Filter Fields
Page Layout
Duplicate Management
Record Types
Lightning Record Page
Force.com Sites
Data Management
Analytic Snapshots
Import Accounts/Contacts
Import Leads
Import Solutions
Import Custom Objects
Data Export
Storage Usage
Mass Transfer Records
Mass Delete Records
Mass Transfer Approval Requests
Mass Update Addresses
Data Loader
Tags in Salesforce
Schema Builder
Process Builder
Flows
Community/Experience Cloud
Chat
Embedded Service Deployment
Einstein Bot
Quick Text
Custom Label
Custom Settings
Custom Metadata Type
Level 2(Coding and Development)
Visualforce Page
Aura Component
LWC or Lightning Web Component
Apex Class
1. Custom Controller and Extensions
2. Best Practices
3. Data Types
4. Batch Apex
5. Future Methods
6. Queueable Interface
7. Unit Testing or Test Class
8. Debugging
9. With Sharing and Without Sharing in Apex Classes
Apex Trigger
1. Trigger development with handler classes
2. Best Practices
3. Recursive Trigger
Integration
1. Standard REST API
2. Outbound REST API with XML Response using Apex
3. Outbound REST API with JSON Response using Apex
4. Inbound REST API using Apex
5. Outbound SOAP API using Apex
Governor Limits in Salesforce
Order of Execution in Salesforce
SOQL