OST or Offline Storage Files represent the user's mailbox data in offline mode on the local machine upon registration with Exchange Server using Microsoft Outlook. It is automatically created on the first use of Microsoft Outlook upon connectivity with the server. Once the file is created, the data is synchronized with the email server so that it is available offline as well in case of disconnectivity from the email server.
Files with .DCM extension represent a digital image that stores medical information of patients such as MRIs, CT scans, and ultrasound images. DCM files use DICOM (Digital Imaging and Communications in Medicine) image file format and can include patient’s information for reference. It was developed by the National Electrical Manufacturers Association (NEMA) and was meant to standardize the imaging file format for distribution and viewing of medical images.
You can also convert OST into many other file formats. Please see the complete list below.