Sometime after Dick became Nightwing, Barbara retired her Batgirl identity. Soon afterward, The Joker tracked Barbara down and damaged her spine, making her paralysed through the waistline down. After the event, Barbara resolved not to let this ruin her life and became some type of computer hacker referred to as Oracle.
Dick Grayson and Barbara Gordon first came across whenever Dick had been simply Robin and Barbara recently beginning her work as Batgirl. The two only interacted as buddies in addition to lovers, as a result Dick devolped a crush on Barbara.
Jason Bard happens to be another strong interest of Barbara post-Crisis on Inifinite Earths because well as during Rebirth.