I sometimes see different error codes. What do they mean?

 In

2 File not found.
3 Path not found.
4 Too many open files.
5 File access denied.
6 Invalid file handle.
8 Out of memory.
10 Error write sort.
13 Cannot initialize modem.
15 Invalid drive.
100 Disk read error – attempt to read beyond end of file.
101 Disk full.
102 File not assigned.
103 File not open.
104 File not open for input.
105 File not open for output.
150 Disk is write protected.
151 Unknown unit.
152 Drive not ready.
154 CRC error in data.
155 Bad drive request structure length.
156 Disk seek error.
157 Unknown media type.
158 Sector not found.
159 Printer out of paper.
160 Device write fault.
161 Device read fault.
162 Hardware failure.
163 Network error.
176 Critical error undefined.
200 Division by zero.
203 Heap overflow.
204 Invalid pointer.
1003 Invalid recotd size.
1004 Index file built with different page size.
1005 Not enough memory.