Session
Session
The continuous exchange between a visitor and a website, lasting from when they arrive until they leave.
In Simple Terms
A session is the ongoing connection between a visitor and a website, lasting from the moment they open a page until they close it. For example, when you add an item to your cart on an online store and then browse other pages, the cart doesn't empty out — that's because the session is still active. This connection automatically ends when you close your browser or after a certain period of inactivity.
Behind the Name
In English, "session" refers to a meeting, gathering, or period of activity — like a work session or a school session. IT borrowed this word to describe the period from when a user connects to a system or website until they disconnect, comparing that ongoing exchange to the duration of a meeting.
Take a Closer Look!
Put simply, a session is the connected state that spans from when a user accesses a website to when they finish their activities and leave — the whole "start to finish" period.
The basic mechanism behind internet communication treats each exchange as independent, with no memory of what came before or after.
To let a web server remember that the same person is browsing continuously, the concept of a session is used.
This is what lets you stay logged in while moving between different pages, or carry over information you entered and submitted on an earlier page of a multi-step signup form.
To manage sessions, the server issues each visitor a unique marker called a "session ID."
Each time the browser moves to a new page, it presents this same marker to the server, which recognizes it as coming from the same person.
From a security standpoint, if this ID is stolen, someone else could impersonate the user — so measures like encrypting the communication are used to protect it.