Hello,

Theoratically, Salesforce1 is a new platform, complete with a host of new APIs and mobile UI tools. To oversimplify it, it's taking the Chatter mobile app, which up until this point has just been an app running on closed source code and building it into a platform, while really blowing out its capabilities. (This is the salesforce-ic definition.)

In simple terms, Salesforce 1 is basically a mobile release version for salesforce. It can be installed and worked upon on Android, ios and blackberry devices. Download it from the playstore and take a hands-on.

Here’s an overview of what Salesforce1 offers.

Collaborate on the go

Access Chatter feeds, groups, people, and files to stay connected to colleagues and customers on the go, keep tabs on records you’re following, and share files from anywhere.

Work faster
Log calls, add meeting notes, create and update records, and more...right in the feed.

Keep up to date with your customers
Reach out to accounts and contacts directly from their Salesforce records, log calls and emails after you make them, and keep current on news about your customers.

Stay on top of your CRM data
Create and edit sales, service, marketing, and custom object records right from your mobile device—no more scribbling notes on scrap paper after client meetings so you can update records when you’re back at your desk.

Track your activities
Manage your time in the field effectively: Use lists to track and manage tasks, close or reopen tasks with one tap, create tasks and events on the spot, and view existing Salesforce events.

Measure your progress
Monitor dashboards to stay current on whatever you’re measuring, wherever you are.

Customize the Salesforce1 experience
Create and integrate mobile-optimized Visualforce pages and custom publisher actions to put custom tools, functionality, and user interfaces at users’ fingertips.

Feel secure
Salesforce1 uses the same level of identity and security as the full Salesforce site, which means your data is as safe when you’re working on your mobile device as it is when you’re working on your desktop.

Note : Please mark this answer as Best Answer if it helps you in giving atleast a blur surface understanding about Salesforce1. Doing this, will help the community to directly refer to this answer.

Thanks !! :)