In Draftboard, a Target is a specific person while an Account is a specific company - so Satya Nadella would be the Target, and Microsoft would be the associated Account.
In different contexts, a 'Target' can mean different things - if you're using Draftboard for:
Sales or Business Development, then these are your Prospects / Leads (e.g. you're trying to get intros to your sales / BD prospects so you can sell them your product or partner with them)
Recruiting or Search, then these are your Candidates (e.g. you're trying to get intros to candidates for the purpose of hiring them)
Fundraising, then these are your Leads (e.g. you're trying to get intros to investors for the purpose of raising capital from them)
Similarly for Accounts - if you're using Draftboard for:
Sales or Business Development, then these are your Accounts (e.g. you're trying to sell into our partner with specific companies)
Recruiting or Search, then these are your candidates Current Employers (e.g. this is where your target Candidates are currently employed)
Fundraising, then these are your Firms/Funds (e.g. these are the firms/funds that you're trying to get in front of)