Why Does Windows 10 Abbreviate File Names?

I've used Linux for about five years and just switched to Windows 10, and it seems that file names are being abbreviated by the new system. This was obvious when I copied some document files to the new system, and not recognizing my files is rather disorienting. I know that DOS had a limit on the number of characters in a file name, but I can't believe that's still the case. Is there a way to show the full names, or did Windows do a permanent rename?

Please post a screenshot showing the issue. Otherwise it is all just guesswork.
Short file names are what they are and cannot be changed. Any changes would have massive compatibility problems.

My guess is that in File Explorer you are seeing what appears to be shortened names but the Columns are too narrow. Move the mouse pointer to the Name heading then carefully move it to the right until it turns to a 2-headed arrow. Click at that point the drag it to the right to widen the column. You can also double-click at the same point to widen the column to the width of the longest file name in that Folder. There's other things you can do with the columns such as rearranging by newest or oldest date, alphabetically A to Z or Z to A, rearrange by size of files, largest to smallest or other way around, etc. A lot of that ability suggests what can be done in a spreadsheet.

As for the actual length, DOS uses the 8.3 scheme, up to 8 characters for the name and up to 3 characters for the extension. Windows 95 introduced LFN/Long File Names and the use of up to about 256 characters but also kept the 8.3 scheme for compatibility with DOS [stored both names on the hard drive].