What methods can be used to present logs for system analysis and monitoring?

Logs for analysis and monitoring can be represented in the following ways:

• Text files: the classic method, logs are written to files, which are then parsed and analyzed.
• Structured logs: JSON or another format, convenient for automatic parsing and searching.
• Centralized logging systems: for example, ELK Stack (Elasticsearch, Logstash, Kibana), Graylog, Splunk — collect logs from different services, index and visualize them.
• Metrics and alerts: transforming logs into metrics (via Prometheus, Grafana) for system monitoring.
• Use of agents: Fluentd, Filebeat — collect and send logs to centralized storage.

Example: an application writes structured logs in JSON, Filebeat collects them and sends to Elasticsearch, where Kibana displays dashboards with key metrics and errors.