what is the point of matching JFETs?

As above. Another question please: what do you call the "purpose/arrangement" (unsure of the proper terminology) of these JFETs in the circuit?

sample Schematic:

Screenshot 2022-12-07 021336-1.png

NOTES:
  1. The unidentified opamp to the left of the OP27 is the bigger circuit above it.
  2. The dual JFETs will be subsituted with 2x of their single counterparts.
 
Stability issues, signal headroom, lower degeneration (large open loop gain), to name some.
Just explained today to my trainee at my work the strategy of matching j-fets: same Idss, Upo or transfer function (S)?
It's a scattered field of parts to choose from. All choices are less ideal for various reasons. The trade off of same die semi's is the risk of a higher noise floor, but manageable.
 
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