Infrastructure Automation is the process of scripting environments - from installing an operating system, to installing and configuring servers on instances, to configuring how the instances and software communicate with one another.

Key components:
1. **Provisioning:**
   - Resource creation
   - Configuration management
   - Application deployment

2. **Orchestration:**
   - Workflow automation
   - Service coordination
   - Resource scheduling

GitOps is a way of implementing Continuous Deployment for cloud native applications. It focuses on a developer-centric experience when operating infrastructure, by using tools developers are already familiar with, including Git and Continuous Deployment tools.

Principles:
1. **Declarative:**
   - Infrastructure as code
   - Application configuration as code

2. **Version Controlled:**
   - Git as single source of truth
   - Audit trail for changes

3. **Automated:**
   - Pull-based deployment
   - Continuous reconciliation

ArgoCD is a declarative, GitOps continuous delivery tool for Kubernetes. It allows you to declaratively manage your Kubernetes applications by using Git repositories as the source of truth.

Key features:
1. **Declarative:**
   - Infrastructure as code
   - Application configuration as code

2. **Version Controlled:**
   - Git as single source of truth
   - Audit trail for changes

3. **Automated:**
   - Pull-based deployment
   - Continuous reconciliation

Tekton is an open-source, cloud-native CI/CD framework that allows you to define, run, and observe CI/CD pipelines. It's designed to be extensible and can be used with any container runtime.

Key features:
1. **Extensible:**
   - Custom tasks
   - Custom resources
   - Custom pipelines

2. **Cloud-native:**
   - Container-based
   - Kubernetes-native
   - Serverless-friendly

Deployment Strategies are methods used to deploy applications to Kubernetes clusters. Common strategies include:

1. **Blue-Green Deployment:**
   - Deploy a new version of the application
   - Traffic is routed to the new version
   - Old version is kept running

2. **Canary Deployment:**
   - Deploy a new version of the application
   - Traffic is routed to the new version
   - Old version is kept running

3. **Rolling Update:**
   - Deploy a new version of the application
   - Old version is gradually replaced
   - Traffic is routed to the new version

4. **Blue-Green with Rolling Update:**
   - Deploy a new version of the application
   - Traffic is routed to the new version
   - Old version is gradually replaced