What is the purpose of CRM systems like Salesforce?

Could you please explain what is the purpose of Salesforce CRM?

Why people say salesforce is the best one?
Hi, I have already shoveled a couple of articles on the topic and each one claims, that it is a CRM system designed to ease control over your business. How they would ease the control?
I’ll really appreciate the answer

Advanced Web Care Professional Web Development

SalesForce refers to customer relationship management systems (CRM, CRM-system).

In short, this is a service for maintaining a customer database (names, contacts), conducting transactions (orders, sales, payments), documents circulation (bids, contracts, receipts). Usually it is multi-user systems. Typically, these systems have integration with other third party for doing email, sms and voice mailings with reminders of transactions or for promotional purposes. Usually there is an opportunity to conduct tasks, transfer them between employees, track performance, deadlines. Typically, such systems can interact with customers on the basis of automated scripts, such as registering orders from the site or conducting surveys on the quality of service.

The purpose of Salesforce and their ilk is to not lose customers and money.

CRM systems can usually build statistical and analytical reports to determine customer satisfaction, employee performance, and global of the state of the organization. According to these reports, you can determine the profitability in general and in particular sectors, shortage or surplus of personnel, the most promising or dead-end channels to attract customers, the most profitable or unprofitable products.

When I say 'usually' it means that it is possible, but not necessarily present in the basic version of Salesforce.
Additions to the basic version are connected to the core separately or custom programmed. SalesForce has an open API which means you can add a custom developed modules, expand the system, narrow it down to your own needs.