A CRM records who your customers and prospects are, what has been said to them, what has been quoted and what happens next. Instead of details scattered across inboxes, spreadsheets and notebooks, the whole history sits in one place that the right people can see.
A joiner who has been talking to a customer for months can go on holiday without the relationship stalling, because a colleague can open the record and see exactly where things stand. A CRM works best when it connects to the rest of the business, such as quoting, delivery and invoicing, rather than standing alone.