Where will the data be deleted after being deleted from memory?

You must first understand the concept of a filesystem. When you press shift + delete, the OS calls the File System procedure to delete the file from the input table. The file system could either choose to simply delete the entry (mark the file as deleted) or zero out the file's data and then delete it from the input table. In case of change + deletion, the File system ensures that you delete the file permanently, that is, zero the data and delete the entry from the catalog table. In this case, it cannot be restored. Although some hardware hacks allow data recovery by analyzing magnetic fingerprints on the hard drive.
If you delete a file by simply pressing the "Delete" key; In fact, it just marks the file as deleted in the file system entry, so the file system can use that data sector and overwrite with other content. In this case, the file can be restored, but it is not guaranteed to be 100%. The file system could corrupt it by overwriting its data sector.