With the devolution settlement of 1998, a new legislative tier was added to government north of the border, bringing with it 129 MSPs.

The number of civil servants and ministers, whose job it is to make policies a reality, also grew dramatically.

With so many new faces and structures it was inevitable that a degree of public confusion would arise over what the new institutions would and could do.

So, why have a Scottish Parliament in the first place if the Westminster parliament had been effectively running the whole of the UK for 300 years?

DEVOLVED POWERS Justice - including criminal and civil law, police, fire, prisons, courts and freedom of information Education - from pre-school through to further and higher education Health and community care - including control of NHS, community care and food safety Enterprise - including business and industry, trade and inward investment and energy Local government - including structure, finance and electoral system Finance - including control of the budget and power to vary the basic rate of tax by up to 3% Environment and rural development - including agriculture, fisheries and forestry, renewable energy, land reform and rural development Social justice - including housing, equality issues and the public sector Transport - including roads, rail and other forms of transport Culture, tourism and sport - including heritage, architecture, Historic Scotland and lottery funding

The simple answer is that when Labour came to power in 1997 it had a manifesto commitment to devolution.

It argued that a decentralised and devolved government structure would give Scotland greater say over its own affairs and in doing so strengthen the UK.

One year later the Scotland Act was passed providing "for the establishment of a Scottish Parliament".

This process, known as devolution, would effectively transfer a whole swathe of law making and administrative powers from Westminster to the Scottish Parliament and Scottish Executive.

Under the terms of the Act, the Scottish Parliament is able to pass laws on issues such as health, education, transport, justice, enterprise, culture, social justice, public services and the environment.

In effect there are many more - including the power to raise or lower tax by 3p - but everything within the parliament's remit is known as a "devolved matter".

The Scotland Act also specifies a range of "reserved matters" on which the Scottish Parliament cannot pass legislation, including foreign policy, defence and national security.

Again, there are many more, but the Act outlines the parameters which the Scottish parliament must work within.

One of the key roles of the parliament north of the border is to hold the Scottish Executive to account, just like Westminster's role in putting checks and balances on the UK government.

Members of the Scottish Parliament, MSPs, can use oral and written questions to hold the executive to account.

They can also scrutinise the work of the executive through their membership of the parliament's many committees.

Each committee must have between five and 15 members which reflect the balance of the parties within the parliament.

Other key roles include;

• to make or amend laws on devolved matters by passing legislation

• to debate important topical issues

• and to conduct inquiries and publish reports on matters of public interest.

All new laws start life in the parliament as bills. These can be originated by the Scottish Executive; a Scottish Parliament committee; any MSP through a Member's Bill; and any person through a Private Bill.

To become law, any bill must successfully negotiate three stages in the Scottish Parliament.

During stage one, MSPs consider the general principles of the bill in one of the relevant committees and hold a debate in the parliament.

At the second stage, the bill is given further scrutiny by MSPs in the relevant committee, and subject to amendment.

Only after this, does the bill enter its third and final stage where MSPs in the parliament vote to pass or reject it.

If it is passed then Royal Assent is given and the bill becomes an Act of the Scottish Parliament.