Sometimes I use these terms loosely. Here an article that explain the 3 fiber optic transceivers QSFP, QSFP+ and QSFP28

Taken from the article “Difference between QSFP, QSFP+, QSFP28“

Here are some main points

1. The QSFP specification supports Ethernet, Fibre Channel, InfiniBand and SONET/SDH standards with different data rate options.
   
2. QSFP transceivers support the network link over singlemode or multimode fiber patch cable.
   
3. Common ones are 4x10G QSFP+, 4x28G QSFP28
   
4. QSFP+ are designed to support 40G Ethernet, Serial Attached SCSI, QDR (40G) and FDR (56G) Infiniband, and other communication standards
   
5. QSFP+ modules integrate 4 transmit and 4 receive channels plus sideband signals. Then QSFP+ modules can break out into 4x10G lanes. 
   
6. QSFP28 is a hot-pluggable transceiver module designed for 100G data rate.
   
7. QSFP28 integrates 4 transmit and 4 receiver channels. “28” means each lane carries up to 28G data rate.
   
8. QSFP28 can do 4x25G breakout connection, 2x50G breakout, or 1x100G depending on the transceiver used.
   
9. Usually QSFP28 modules can’t break out into 10G links. But it’s another case to insert a QSFP28 module into a QSFP+ port if switches support.
   
10. QSFP+ and QSFP28 modules can support both short and long-haul transmission.