Repo = Security providers eg banks lend cash to the RBA, RBA lends bonds in return. Reverse-repo = RBA lends cash to security providers eg banks, banks lend bonds to RBA in return. For anyone interested in reading about the repo market in Australia, see: https://www.rba.gov.au/publications/bulletin/2010/dec/pdf/bu-1210-4.pdf
^ security providers are posting collateral at the RBA in the form of cash balances or bonds, it depends which direction the repurchase agreement is going. The bonds could be issued by Federal, State government or corporate entities, and mortgage backed securities (MBS) etc. See: https://www.rba.gov.au/mkt-operations/resources/tech-notes/eligible-securities.html for a list of eligible securities.
Overnight Reverse Repurchase Agreements: Treasury Securities Sold by the Federal Reserve in the Temporary Open Market Operations. RRP (blue line) v BTC price (red):