A lot of casters are now talking about team line-ups having "sustain". What's being referred to is the ability of a team to replenish health and mana on an ongoing basis, so the team can keep fighting or pushing.
How to get "sustain"?
Items for Supports:
- Arcane Boots
Items for Carries:
- Hp-regen items (BFury, Bloodstone, etc)
- Lifesteal items (MoM, HoD, Vlad's)
- Early Mekanism (built on mid-heroes such as SFiend, Viper, Dragon Knight)
- At least 1 healer (see List of Healers)
- Pick heroes with low-cooldown ultimates
Why is this important?
In the "fighting meta" of the 6.85 patch, a won team fight can often result in large gains (i.e. some kills and more than 1 tower), if the team has the items and abilities that they need, to avoid returning to base.