Probate Court Procedure: Administrator, Applicant and Conversion

My question involves estate proceedings in the state of: Texas

When visiting the Clerks' Office case of a Dependent Administration Probate case, the Administrator's role is mentioned as "Applicant" and also as "Conversion".
Could you kindly inform me what is the exact meaning and role of "Conversion".

Thank you in advance

Probate Court Procedure: Administrator, Applicant and Conversion