If you need to connect an RJ45 cable (a.k.a Ethernet) to a board that with an Ethernet Jack - this adapter will come in very handy! No soldering required. Just use a slim screwdriver to open up the terminal blocks, slide in your stranded or solid-core wire and re-tighten. Note that these aren't recommended for actual Ethernet traffic, especially long term...but for basic power/data distribution, RJ45's are great!
This is the Ethernet (RJ45) Male Plug Terminal Block. There is a standard RJ45 Ethernet plug on one end, and a screw terminal block on the other.