The indicative mood is used for statements of fact or opinion. It's the mood we use for most everyday conversation and writing. Here are some examples:
* "I am going to the store." (Statement of fact)
* "The sky is blue." (Statement of fact)
* "I think it will rain today." (Statement of opinion)
While other moods exist (like the imperative mood for commands and the subjunctive mood for hypothetical situations), the indicative mood is by far the most frequently used.