These are the skills that your character has developed during their day to day role. You have 50 points to spend on the ten skills under your character's career. You can choose not to take some skills if you wish. If you think that 50 points isn't enough, have a look at the quirks section to increase your skill pools.
Example: Drake is a government agent and has the following skill choices:
Command, criminology, facilities (type), interrogation, interview, melee (type) / unarmed combat, perception package, pistol, psychology, writing.
The slash between melee and unarmed combat indicates that I must choose one of those two skills for Drake. I choose unarmed combat for him.
Where it says facilities (type), it means that there are different topics, or areas, covered by that skills. Facilities is a skill dealing with obtaining things through legal channels (mostly). I pick facilities (info), so Drake can find out what's going on.
From the perception package I choose perception (visual) and perception (listen).
You can browse the careers section here.
These are skills that your character has learned through hobbies, school or just picked up along the way. Not everyone gets the same breaks in life, so there are different social backgrounds to choose from. They are: corporate kid, normal, streetkid, clansman, highrider and military. Whatever a character's background everyone gets 50 points to spend (subject to picking any quirks).
There is also a section marked universal that all characters can choose from. The education section is only open to those backgrounds with the education option. However, for extra points, you can get skills that are listed in another social group's options.
Corporate brats are people sent off to private schools, home education networks or even educated by their nanny. They don't tend to be worldly wise due to their sheltered upbringing.
Burb kids are from the suburbs and posh housing projects. They include the middle class and low income kids who got some schooling from the suburbs. Not all tenant children are wise ass street trash.
Streetkids run riot on the street as homeless or in crap housing projects. The world is not always a kind place and many die young. Those that don't, might make it - well they'll live a bit longer anyway.
Clansmen are the mobile crusties, they drift from sprawl to sprawl looking for work. Some even abandon society to join extended families; moving to self-sufficiency or sponging off the state. Romantic it isn't.
Highriders are people who lived in low earth orbit. In space, ignorance kills.
The Miliary still has it's own schools, jobs for life and places to live. Some people never see civilian life until they get injured and ditched; or just ditched.
For more information, see the pick up skills section
A full description of each skill can be found here. There are skills for all of the skill bases: knowledge, agility, manipulation, communications, tech, perception and miscellaneous. Sorcery is covered under the magic chapter.