updating code snippets images

Signed-off-by: ahmedEid1 <[email protected]>

Author: ahmedEid1

COBOL Programming Course #1 - Getting Started/COBOL Programming Course #1 - Getting Started.md

@@ -2392,7 +2392,7 @@ A dataset has many records.  A record is a single line in the dataset and has a
 
 Each record read by the program can result in disk storage access.   A program typically reads 1 record at a time in sequential order until all records are read.  When a record is read, the record retrieved from disk is stored in memory for program access.  When each next record read requires the need to retrieve the record from disk, system performance is impacted negatively.  Records can be blocked where a block is a group of records.  The result is when the first record is read, then an entire block of records is read into memory assuming the program will be reading the second, third, etc. records avoiding unnecessary disk retrievals and negative system performance.  The memory holding a record or block of records to be read by the program is known as a buffer.  COBOL BLOCK CONTAINS clause is available to specify the size of the block in the buffer.  Observe Figure  3.
 
-![](Images/image127.jpg)
+![](Images/image127.png)
 
 *Figure  3.  Records, fields, and blocks*