what is indefinite tense

Here is a simpler explanation of the present indefinite tense or the simple present tense:

Some actions or events occur for which we cannot point our the exact point of time except that they occur in the present moment. To express such situations we use a particular form of the present tense called the present indefinite tense or simple present tense. For example: I go, I eat, I sleep, The Sun rises in the east, etc.