What social media actually does
Social media is a platform where you create a profile, post text or photos, and connect with other people. The platform stores your information, shows your posts to people you choose, and lets you see posts from people you follow. Facebook, Instagram, TikTok, X (formerly Twitter), and LinkedIn are the largest ones, but there are dozens of smaller networks built around specific interests.
The core mechanic is the same across all of them: you upload content, the platform decides who sees it based on its algorithm, and people can react by liking, commenting, or sharing. The platform also collects data about what you post, what you look at, how long you spend looking at it, and who you interact with. That data is how these companies make money — they sell advertising space to businesses who want to reach people like you.
Understanding how this works matters because it shapes what you see, how much time you spend there, and what information about you exists in a company's database. None of this is hidden, but it is not always obvious either.
Key Takeaways
- Social media platforms make money by selling ads, so they design their systems to keep you scrolling longer and show you content that makes you engage more.
- Everything you post — photos, location, interests, who you follow — is stored by the company and can be used to target ads at you or sold to advertisers in anonymized form.
- The algorithm that decides what you see is not random; it prioritizes posts that get reactions, which often means divisive or emotionally intense content ranks higher.
- Deleting a post does not delete it from the company's servers, and deactivating your account does not delete your data — you have to request deletion separately.
- Different platforms have different rules about what you can post, who can see your information, and how long they keep your data after you leave.
How the algorithm decides what you see
When you open a social media app, you do not see every post from every person you follow in the order they were posted. Instead, the platform's algorithm picks which posts to show you, in which order. The algorithm looks at what you have engaged with before — what you liked, commented on, or spent time looking at — and shows you more of that kind of content.
This creates a feedback loop. If you watch a lot of videos about cooking, the algorithm will show you more cooking videos. If you interact with political posts from one viewpoint, you will see more posts from that viewpoint. The algorithm is not trying to show you the truth or a balanced view; it is trying to show you content that will make you click, like, or comment, because engagement keeps you on the platform longer.
This means the content you see is not the same as the content your friends see, even if you follow the same people. Two people looking at the same platform at the same time will see a different feed because the algorithm customizes it for each person based on their history.
What data these platforms collect and store
When you create an account, you give the platform your name, email, phone number, and birth date. From that point on, the platform tracks what you post, what you look at, how long you look at it, where you are when you use the app, what device you use, and who you interact with. If you upload photos, the platform can identify faces in them. If you use location services, it knows where you are.
This data is stored on the company's servers indefinitely, even if you delete the post or deactivate your account. Deactivating an account hides your profile from other users but does not delete your data. To actually remove your information, you have to request deletion through the platform's settings, and even then the company may keep some data for legal or operational reasons.
The platform uses this data to build a profile of you — your interests, your political leanings, your shopping habits, your relationship status, your health concerns — and sells access to that profile to advertisers. You do not see the money; the advertiser pays the platform to show ads to people matching your profile. Some platforms also sell anonymized data to data brokers, who package it and sell it to other companies.
Privacy settings and what they actually control
Every major social media platform has privacy settings that let you control who sees your posts and who can contact you. These settings are real and do work — if you set your profile to private, only people you approve can see your posts. If you turn off location sharing, the platform will not track your location.
What privacy settings do not control is what the platform itself collects. Even if your profile is completely private and you post nothing, the platform still knows what you look at, how long you look at it, what device you use, and where you are. The data collection happens whether you use privacy settings or not. Privacy settings only control what other users can see, not what the company can see.
You can limit some data collection by turning off location services, disabling cookies in your browser, or not uploading photos. But the platform will still collect basic information about your account activity. If you want to stop all data collection, you have to not use the platform.
How to control what you post and who sees it
Before you post anything, check your privacy settings. Most platforms let you choose whether each post is visible to everyone, only to friends, or only to you. You can also control who can comment on your posts and who can message you. These settings are usually in a menu labeled "Privacy" or "Settings."
Remember that even if you set a post to private, anyone you share it with can screenshot it or share it with others. The platform cannot prevent that. Also, if you post something and then change your privacy settings later, people who saw it before the change may still have seen it.
If you want to remove something you posted, you can delete it. The post will no longer appear on your profile or in other people's feeds. However, the platform's servers still have a record of it, and if someone screenshotted it, they still have a copy. Deletion removes it from public view but not from the company's database.
Different platforms, different rules
Facebook, Instagram, TikTok, X, and LinkedIn all have different policies about what you can post, how they use your data, and how long they keep it. Facebook and Instagram are owned by the same company (Meta) and share some data between them. TikTok is owned by a Chinese company and has different data storage rules. X has fewer content moderation rules than most platforms. LinkedIn is designed for professional networking and has different privacy defaults than social platforms.
Before you create an account, read the platform's terms of service or privacy policy if you want to know exactly what data they collect and how they use it. These documents are long and written in legal language, but they are the only place where a platform legally commits to how it will handle your information. The privacy policy is usually linked at the bottom of the website or in the app's settings.
If a platform changes its terms of service, it will usually notify you, but you may have to actively accept the new terms to keep using it. If you do not agree with the new terms, you can deactivate your account.
Risks and things to watch for
The main risks of using social media are spending more time than you intend, seeing content designed to upset you, and having your personal information used in ways you did not expect. The algorithm is designed to keep you scrolling, so if you find yourself spending hours on these platforms when you meant to spend minutes, that is by design, not an accident.
Scammers also use social media to impersonate people, sell fake products, or trick you into sending money or personal information. If someone you do not know messages you asking for money or personal details, it is almost certainly a scam. If someone claiming to be a friend asks you to send money urgently, contact that friend through another method before you send anything.
Your posts can also be used against you. Employers, schools, and other organizations sometimes search social media to learn about people. Posts you made years ago can resurface. If you post something you would not want a potential employer to see, consider whether you really want to post it.
Frequently Asked Questions
Can I delete my account and all my data?
You can deactivate your account, which hides your profile, but the platform keeps your data. To delete your data, you have to request deletion through the platform's settings. Even after deletion, the company may keep some data for legal reasons or if it has already been shared with advertisers. The deletion process can take weeks or months.
If I use private settings, can the platform still see what I post?
Yes. Private settings control what other users see, not what the platform sees. The company can see all your posts, messages, and activity regardless of your privacy settings. The only way to prevent the platform from seeing something is to not post it.
Do I have to use my real name?
Most platforms require you to use a name you go by in real life, but the rules vary. Facebook requires your real name. Instagram and TikTok let you use a username instead. X lets you use any name. Check the platform's rules before you create an account if this matters to you.
Why do I see ads for things I just talked about?
The platform is tracking what you look at and what you talk about, and selling that information to advertisers. Some of this happens through the app itself. Some happens through tracking pixels on websites you visit — small pieces of code that tell advertisers you visited that site. Turning off location services and limiting app permissions can reduce this, but not eliminate it.
What happens to my photos after I post them?
The platform stores them on its servers. If you delete the post, the photo is no longer visible to other users, but the platform keeps a copy. The platform can use the photos to train facial recognition systems or to show them in ads. If you do not want a photo stored by a company, do not post it on social media.