A my client center (MCC) allows you to link multiple account together. An adwords account is a collection of campaigns and adgroups.
At the account level, you set your e-mail access preferences, notifications preferences, billing preferences and other linked accounts.
At the Campaign level you choose the networks where your ads will be displayed.
Budgets, Location and Language setting the campaign level.
Campaigns should be organized similar themes or businesse objectives.
Ad groups are a collection of Ads and keywords.
Ad groups should be highly related themes.