Typically (in the US at least) the term "socially conservative" is used to specify conservatism on social (usually domestic) issues, as opposed to other areas like foreign policy, economy, or some other broad subject of government.

Within that framework, you'll usually see "social conservatives" holding views that are often considered "family values" positions (for better or for worse), and usually are primarily concerned with subjects surrounding the day to day lives of the individuals within society.

These positions are often closely tied to personally held beliefs on the ways that society overall should look and act, and as such are frequently informed by religious beliefs (which tend to focus on the same topics). Such issues include: abortion (with social conservatives tending to be pro-life to some degree), LGBTQ rights (typically anti-marriage equality, against recognition of trans gendering, and any and all depictions of non-cishet lives in any books, movies, etc. especially those marketed toward children), public school curricula (if anyone is talking about banking books, it's likely social conservatives), the role of religion in schools and other official places (frequently they're very much in favor of prayer in schools...so long as it's Christian prayer... American social conservatives would very likely blow a fuse if their kid's school were to have prayer times for their Muslim students), content and conduct deemed 'offensive' (profanity in songs, violence in video games, etc.), sex and nudity, censorship, etc.

Simply put, they're the "Won't someone think of the children!" people who want to tell everyone else how to live their lives.