Familiar to means
known to. If someone or something is familiar to you, you recognize it well.
- His work is familiar to me.
- Her face is familiar to the crowd.
- This tune is familiar to most of the singers.
- The appearance of the Polar bear is familiar to all.
- The name of the school was not familiar to me.
Familiar with means having a fairly good knowledge of. If you are familiar with something, you know or understand it well.
- He is familiar with the countryside.
- Sam was familiar with those streets.
- Eva is quite familiar with Central Television; she worked there for 5 years.
- I'm familiar with various teaching software packages.
- I’m not familiar with the latest research in this field.