"Feed" will be the line from the phone company. It's the source of your phone and DSL. (I presume.) It probably runs to a phone company box (the "demarc" or "demarcation point"...the phone company is responsible up to there...beyond that you are) outside your house. IOW, "FEED" is "IN", the rest are various "OUT"s. In an older house all the jack cables would begin at the demarc and then go from jack to jack.
That long blue/white pair winding in and out of your 66 block is a bus spreading the feed to your station runs (cat 5 cables to bedroom, kitchen, etc). We cheated a little bit and teed off from that bus with bridge clips to feed your dsl line. (Actually there's nothing technically wrong with it; it's just an inconsistent type of hookup within your block.)
BTW, illegal aliens could have provided this info to you much more cheaply while still contributing to the economy via consumption and encouraging growth.
EDIT: LOL, these context-sensitive ads can be sharp sometimes. This is an ER forum, but the ad at the bottom of this thread was "Great Cables", a cabling company.