Is there any difference between NIST and SECP curves in-terms of their algorithms and implementation? I'm implementing ECDSA for NIST P-256 curve. I just want to know if the same implementation will also work for SECP curves? If it doesn't, can you point me to one or more references of algorithms for SECP 256?

To clarify: I specifically want to know if there are any differences in algorithms for point addition and point scalar multiplication. For the current NIST implementation I'm using projective coordinates for point addition and multiplication.
Please check https://tools.ietf.org/search/rfc4492 - espessially, the "Appendix A.  Equivalent Curves (Informative)" part. 

For example: NIST P-256 is refered to as secp256r1 and prime256v1. Different names, but they are all the same.