Even the most well-seasoned of hiring managers and HR specialists will occasionally confuse and use job ads and job descriptions interchangeably. It’s crucially important to differentiate between them though - they serve two very different purposes!
1. A job description describes what the Candidate does for you; an ad should focus on what you can do for them
Let’s go back to basics quickly: an advertisement is ‘any public notice […] designed to sell goods’. 
It goes without saying then, that an ad should market your business and the position in a positive way; it functions as a sales and brand awareness tool. With this in mind, it makes sense that your job ad would be the place to really sell the benefits. Pique Candidates’ interest by highlighting all the perks you can muster up: from complimentary gym memberships, subsidised meals and car allowances, to the great team, career progression and flexible working arrangements.
A job description, on the other hand, is generally given to those who have taken an interest in the position already, so you know that they’ve actively taken a second step towards finding out more about the business and the role. Here is where you’ll delve into deeper detail about their responsibilities, essential experience and skillsets required.
2. A job description describes the detail; an ad gives an overview
Because the advert needs to draw people in quickly, essays are not going to be effective here. Write your advert once, then edit, and edit again. It does not need to give much more than an overview of the role itself, along with a promise of the unique benefits afforded to them if they’re successful.
When applicants are at the stage that they want to find out more, they’ll read the job description: now feel free to increase your word count and elaborate on the detail. Outline the day-to-day responsibilities so that they can match their experience and assess their fit.
3. A job description is factual; an ad tells the story
A well-written advert should be drafted with flair and imagination; draw your audience in with an interesting story that they can relate to. An exceptionally effective way of capturing their imagination is via multimedia - if your budget can stretch to video or animation, do it!
A job description, by contrast, can be written with the minimum of ‘fluff’. Its purpose is to list the tasks of the role along with required experience. If you’re so inclined, you may add a list of benefits to the bottom too.
4. The job title and jargon may vary
The actual job title you’re recruiting for might be ‘Director of first impressions’, but when advertising, keep it to a simple ‘Receptionist’. Not only will it make the job ad easier to find when Candidates are searching online, it will also receive higher click-throughs. Similarly, avoid any hard-to-understand jargon or acronyms in an ad. You’ll only intimidate readers and dissuade them from applying.
Feel free to include these in your job description, but we’d encourage you to explain them.
5. They’re read by different people, in different ways
An advert will usually be available for everyone to see. Any recruiter or hiring manager will want to maximise the reach of their job advert, sending it to the far corners of social media, job boards and beyond. As Candidates are increasingly browsing on the move using their mobiles and tablets, make it easy for them: optimise your advert for all devices and post it in the places they’re likely to see it. Check for key words and searchable terms to ensure you’re maximising SEO.
A job description, by contrast, will be a longer document sent to engaged Candidates, so feel free to distribute as a pdf or hard copy.
If you’re looking to hire your next star Candidate and need some help, contact Tiger today.
 Collins English Dictionary