Some examples of archives
The archive of a local authority
might contain the minutes of the council and all its committees; reports made to the council and committees; detailed accounts; records of individual departments - a huge range of records reflecting all aspects of the council's work, including planning, highway maintainance, education, care of the elderly and of children, and much more. The archive as a whole will tell us the history of the council, but individual items within it may be relevant to all sorts of research and enquiries.
The archive of a landed family
might contain hundreds of title deeds to the land they own; rentals (lists of rent owed and paid); maps and plans; records of buildings and building work, and of landscaping; accounts; records of business or industrial interests; and personal records - for example letters, diaries, family certificates, wills and photographs. Taken as whole, the archive reveals the history of the family and its interests over many generations; individual items or series of items within the archive may be of vital importance to those studying local history, business history, garden or architectural history or family history.
The archive of a business
might include, amongst other things, the board minutes, accounts, production records, staff records, advertising records, title deeds to property owned, and photographs. The archive as a whole will be a vital source for anyone researching the business itself, but material within the archive may reveal much information to local, house and family historians, while production records may be of enormous interest to those with specialist research interests - and advertising records and photographs can provide a fascinating window on the past for those with just a general interest in history.
A personal archive
might contain records the individual felt were important to them. Most personal archives are kept by the people who created them or by their families, but some - particularly of public figures - may be judged to be specially significant and placed in the care of an archive repository. Such an archive might include many different things - for example diaries, correspondence, photographs, research notes, and drafts of writings. The archive as a whole will be indispensable for an understanding of the person who created it, but individual items within it may be relevant to other areas of research. It's worth noting that the archive will contain only the records created, received or collected by the individual themselves; much other relevant information might be found elsewhere - for example letters the individual wrote will usually remain with the person who received them.