Because shareholders are, in essence, partial owners of the company, they have rights in terms of company governance. It is typical for shareholders to vote on major changes such as changing the company name, removing a director, and making amendments to the company’s articles of association.
When shareholders vote on these types of decisions, it is called “passing a resolution.” An ordinary resolution requires a simple majority (over 50%), whereas a “special” resolution may require more, e.g. a 75% majority vote. Note that each shareholder does not get a single vote; the value of a shareholder’s vote correlates with the amount of shares s/he owns. Therefore, the vote of a shareholder who owns 3% of the company is worth three times that of a shareholder who owns 1% of the company.
Because some shareholders may own more of the company than others, it may not be necessary for all shareholders to vote in order to reach the majority required to pass a resolution. However, regardless of whether or not they participated in the vote, each and every shareholder must be informed of the decision in writing.
See Companies House’s information page for a complete list of changes and resolutions that must be reported by companies limited by shares.