EDIT
I would think that:
*****uncompressed data is data that was never altered
*****decompressed data is data that has been compressed, then returned to its original state by the process of decompression.

Decompress and uncompress seem to be used synonymously in the context of computing, although decompress seems to be used more frequently. A search on MSDN for uncompress* returns 731 hits, while decompress* returns 4,450 hits.

Seaching on SO gives similar results. There are

• 22 questions tagged with uncompress
• none tagged with uncompression,
• 651 occurrences of uncompress and
• 34 occurrences of uncompression.
  Total tag count = 22
  Total word count = 685

In contrast, there are

• 39 questions tagged with decompress
• 110 questions tagged with decompression
• 1,467 occurrences of decompress and
• 865 occurrences of decompression.
  Total tag count = 149
  Total word count = 2,332

EDIT
I would think that:
*****uncompressed data is data that was never altered
*****decompressed data is data that has been compressed, then returned to its original state by the process of decompression.

Decompress and uncompress seem to be used synonymously in the context of computing, although decompress seems to be used more frequently. A search on MSDN for uncompress* returns 731 hits, while decompress* returns 4,450 hits.

Seaching on SO gives similar results. There are

• 22 questions tagged with uncompress
• none tagged with uncompression,
• 651 occurrences of uncompress and
• 34 occurrences of uncompression.
  Total tag count = 22
  Total word count = 685

In contrast, there are

• 39 questions tagged with decompress
• 110 questions tagged with decompression
• 1,467 occurrences of decompress and
• 865 occurrences of decompression.
  Total tag count = 149
  Total word count = 2,332

Decompress and uncompress are used synonymously in the context of computing, although decompress seems to be used more frequently. A search on MSDN for uncompress* returns 731 hits, while decompress* returns 4,450 hits.

Seaching on SO gives similar results. There are

• 22 questions tagged with uncompress
• none tagged with uncompression,
• 651 occurrences of uncompress and
• 34 occurrences of uncompression.
  Total tag count = 22
  Total word count = 685

In contrast, there are

• 39 questions tagged with decompress
• 110 questions tagged with decompression
• 1,467 occurrences of decompress and
• 865 occurrences of decompression.
  Total tag count = 149
  Total word count = 2,332

EDIT
I would think that:
*****uncompressed data is data that was never altered
*****decompressed data is data that has been compressed, then returned to its original state by the process of decompression.

Decompress and uncompress seem to be used synonymously in the context of computing, although decompress seems to be used more frequently. A search on MSDN for uncompress* returns 731 hits, while decompress* returns 4,450 hits.

Seaching on SO gives similar results. There are

• 22 questions tagged with uncompress
• none tagged with uncompression,
• 651 occurrences of uncompress and
• 34 occurrences of uncompression.
  Total tag count = 22
  Total word count = 685

In contrast, there are

• 39 questions tagged with decompress
• 110 questions tagged with decompression
• 1,467 occurrences of decompress and
• 865 occurrences of decompression.
  Total tag count = 149
  Total word count = 2,332