What is the purpose of the oracle to_char function?

The TO_CHAR function in Oracle is used to convert a number, date, time, or string to a character type. It can convert the data to a specified string format based on the provided format model.

Specific functions include:

1. Format date and time: By providing various date and time format patterns, we can format date, time, or timestamp data into any desired string format.
2. Number formatting:
   It is possible to convert numbers into strings and format them according to a specified model, such as specifying decimal places or thousand separators.
3. String conversion: Strings can be converted into different character types and formatted according to requirements.
4. Conversion between numbers and dates: it is possible to convert numbers into dates or dates into numbers.

In conclusion, the TO_CHAR function in Oracle is used to convert numbers, dates, times, or strings into character type, and can be formatted based on the provided format model.