The Sims 2/Needs

Every Sim has basic needs. Hunger, Bladder, Energy, Comfort, Fun, Social, Hygiene, and Environment. This table gives a basic view on how to satisfy needs for your sims. Environment functions differently to other needs so isn't recorded here.

Hunger
To fill hunger, buy a fridge and select it in live mood with your sim. You will eventually need to buy more stock for your fridge, to do that use a phone and click delivery, and then groceries.

Bladder
To fill bladder buy a toilet. Select the toilet in live mood and click "use".

Energy
To fill a sim's energy, buy a bed, couch or a recliner. When selected in live mood you will see, sleep or nap. Beds are best for a sim's energy.

Comfort
To give a sim comfort buy a seat of any kind, a higher-class toilet, a bathtub, a bed or a couch. Select any of the following in live mood: sit, relax, use, bath, sleep or watch TV. There are more options but these are the basics. Expensive couches are best for raising comfort.

Fun
Fun can be raised by, TVs, toys, playing with another sim or entertaining, swimming, reading and lots more. If a sim is serious it would get more fun out of reading a book, if it is playful a toy would be best.

Social
Social can be raised by clicking on another sim a choosing any interaction, calling someone on the phone, the social bunny, talking on chat can all raise social. Kissing and woohoo are the most social raising interactions.

Hygiene
Hygiene is important to your sim so buy it any of these: a bathtub, shower, tap or a mirror, which allows your sim to bush its teeth.

Environment
Environment can be raised by simply not being in a trashed room that has decorations in it.

Need Benefits
When a sim's needs are met their work performance will improve, they can preform more positive interactions between other Sims, they can study better and they will spend less time throwing tantrums. While it may be fun to watch Sims suffer if their needs are not meet they may die and you will need to go to more effort to make another one.