what is upsarg ? give example

Hey buddie ill explain u clearly what upsarg really is.....

see if we take any word ....hmmm for example take paatshala (school in hindi)

here,

paatshala when splitted into 2 words gives  -   paat+shala .......here paat is upsarg and shala is pratyay.....

in short ........jab ke pehle shabdansh ko jodkar uske arth mein vishesh parivartan late hai os shabdansh ko upsarg kehlathe hai
hope u understood it :D