As much part of the college experience as lecture halls and mortar boards, if you're taking up a college place the student union is likely to enter life over the next few years in a myriad ways.

Whereas in the late 1960s many student unions were devoted to overturning the capitalist system and opposing their conservative elders, nowadays such idealism is tempered with pragmatism.

While the unions' leaders are still a thorn in the side of the college authorities, they also concentrate on giving students basic services at good prices - and this is increasingly taking up as much of their time as campaigning.

Some decry the lack of a radical edge, and in response today's student-union leaders point to the range of issues they pursue. These have expanded well beyond anything explored by their more indignant predecessors.

Many would also argue that the unions today face a more complex, often sensitive task, dealing with health, sexual, welfare and race issues - and while a small number have been accused of being po-faced and politically correct, most work hard for their members and most are accessible day or night.

As a student, you are automatically a member of your local student union.

Essentially, the unions are there to look after your interests and to provide the kind of services you need to get through college as smoothly, successfully and enjoyably as possible. The student body is there to judge whether they meet expectations or not.

These local services can include representation on college authorities, a student-run shop, dozens of sports clubs, student societies, large-scale entertainments and a range of other, more mundane services such as photocopying and book-lending.

Averil Power, president of the union at Trinity's College, says student unions are particularly important to people starting college: "College is likely to be different from anything you've ever done before. If you've just finished school, the sense of personal responsibility for your own academic progress will suit some of you but not others," she says.

"If you're a mature student, you may experience particular difficulties getting used to studying again. And if you're an international student, acclimatising to Irish culture may prove more challenging than anything else in the first few weeks.

"One thing's for sure, though - whoever you are, your union is here to represent you and help you make the most of your time."

The Union of Students (USI) in Ireland is the sole national representative body for students.

Founded in 1959, it represents more than 250,000 students in more than 50 colleges across Ireland. USI works to "improve the welfare of all those engaged in post-compulsory education".

Its president, Richard Hammond, says: "It is our job to continually lobby, campaign and raise awareness around the issues that affect our members.

"Whether it is fighting for increased maintenance grants, lobbying for greater rights for students in the private rented sector, or tackling any form of discrimination against students, USI is there to put forward the views of its membership."

USI has 10 full-time officers, all students who have taken time out of their studies to work full-time for the union.

There are also five part-time officers. These are students who, in addition to college work, take on the responsibility for directing USI's campaigning.

As a member of USI you receive benefits during your time in college including

USI membership Card, offering discounts in several retail outlets;

a "fresher's pack";

access to the USI/SIPTU advice line for those experiencing problems at work;

a copy of the free student magazine, Voice.

Hammond says USI is "particularly proud" of its link with the country's largest trade union, SIPTU.

"The link brings together USI's 250,000 members and SIPTU's 220,000 members in a way that benefits both organisations. Students have access to information, advice and consultation in respect of any workplace difficulty. Furthermore, subject to its own rules, SIPTU will accept into full membership any USI member requiring representation concerning a workplace matter, either to a third party or direct to the employer concerned. This is of great assistance to the 53 per cent of our members who work part-time."

To voice students' concerns at national level, USI has representation on a number of key national decision-making bodies.

These include:

the Higher Education Authority,

the National Qualifications Authority of Ireland,

the Higher Education and Training Awards Council,

Irish Council for International Students and

the Higher Education Equality Unit.

"USI's strength ultimately depends on its membership," says Hammond.

"If you want to get involved in improving any aspect of student life, then we want to hear from you."